The World Federation for Ultrasound in Medicine and Biology (WFUMB) has recently launched a project on incidental findings (IF). Incidental findings of almost all organs are common and the topic is, therefore, of importance. This is a new concept of papers following a strictly defined structure and including the following headings: prevalence, epidemiology, clinical significance, clinical scenarios and the role of ultrasound and other imaging methods, summary statements and management strategies. The organs so far discussed in published papers are the adrenal glands, scrotum, salivary glands, spleen, female pelvis, biliary tree and, additionally, the important topic of managing incidental findings reported by medical students performing educational ultrasound examinations. The current paper summarizes IF of the liver in pediatric patients with special attention to the use of radiation-free ultrasound and contrast-enhanced ultrasound (CEUS).The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled “Incidental imaging findings—the role of ultrasound”. IFs in the liver of newborns and children are rare and much less commonly encountered than in adults; as a result, they are relatively much more frequently malignant and life-threatening, even when they are of benign histology. Conventional B-mode ultrasound is the well-established first line imaging modality for the assessment of liver pathology in pediatric patients. US technological advances, resulting in image quality improvement, contrast-enhanced ultrasound (CEUS), liver elastography and quantification tools for steatosis have expanded the use of ultrasound technology in daily practice. The following overview is intended to illustrate incidentally detected liver pathology covering all pediatric ages. It aims to aid the examiner in establishing the final diagnosis. Management of incidentally detected focal liver lesions (FLL) needs to take into account the diagnostic accuracy of each imaging modality, the patient’s safety issues (including ionizing radiation and nephrotoxic contrast agents), the delay in diagnosis, the psychological burden on the patient and the cost for the healthcare system. Moreover, this paper should help the pediatric clinician and ultrasound practitioner to decide which pathologies need no further investigation, which ones require interval imaging and which cases require further and immediate diagnostic procedures. The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications titled “Incidental imaging findings—the role of ultrasound” ,5,6,7,8.An incidental finding (IF) during an imaging examination is the unintended and unexpected discovery of an abnormality that may be clinically significant. IFs on imaging studies are asymptomatic and unexpected pathologies, unrelated to the presenting illness. They often necessitate further imaging or diagnostic work-ups which entail both a psychological and an economic burden for the patient and the healthcare system ,7,8,9,10Liver incidentalomas are commonly encountered with a reported frequency of up to 33% of radiological studies and 50% of autopsies in adult patients ,12, but Ultrasound is the primary modality for the evaluation of liver pathology in children, including liver incidentalomas (IF). Contrast-enhanced ultrasound (CEUS) was introduced more than twenty years ago. The most important indications for using CEUS include: the characterization of indeterminate focal liver lesions using conventional B-mode ultrasound, computed tomography and in staging, and follow-up of previously known focal liver lesions (FLL). The latter includes pediatric patients with known cancer, patients who are under a surveillance program for chronic liver disease or other conditions that predispose them to malignancy ,17,19, aThe European approval study for SonoVue 2001 was published as a first prospective multicenter trial with convincing results . In the Given its well-established role in liver imaging and its advantages over CT and MR imaging—including better patient tolerability, better performance in the presence of parents or caregivers at the point of care (bedside), better performance at the time of primary detection with complete assessment and definitive diagnosis, reduced cost and lack of ionizing radiation, and lack of renal, hepatic, cardiac, cerebral and thyroid toxicity—it has an important role in the evaluation of FLL ,47,48,49More than ten years ago, this project on incidental findings was initiated to, (1) carefully assess the pretest probability which included: presentation of the patient, medical history , assess laboratory data and liver stiffness using elastography and (2) to assess lesion characteristics including size and echogenicity ,51. In aLater, a similar approach was used for guidelines issued by the American College of Radiology (ACR) on the management of liver incidentaloma using CT . It is oPatients with no risk include healthy subjects being examined for screening purposes, patients with low risk of malignancy and those with no history of primary malignancy, no hepatic dysfunction and no risk factors. Patients with a high risk are those with known malignancy that is associated with liver metastases, liver cirrhosis and other hepatic risk factors including hepatitis, non-alcoholic steatohepatitis, alcohol overuse, cholangitis, choledochal cysts, haemochromatosis and other hereditary hepatic conditions or anabolic steroid use . AccordiThe unique role of computed tomography for staging and magnetic resonance imaging for characterization and staging in oncological patients is undoubtedly accepted.How to perform contrast-enhanced ultrasound—including patient preparation , ultrasoComplete or incomplete situs inversus are not frequent incidental findings during ultrasound. Situs inversus is a congenital abnormality in which the heart may be on the right side (“right-hearted”) and/or visceral organs are reversed or mirrored from their normal positions. The reported frequency is about 1/10.000. Most pediatric patients have no medical symptoms or complications; however, a higher rate of cardiac anomalies has been reported. In a few patients with situs ambiguous or heterotaxy, situs cannot be determined. In these patients, the liver may be midline, the spleen absent or multiple, and the bowel malrotated ,63.The measurement of liver size is not generally recommended due to large variations and non-reproducible techniques. The US practitioner must, however, use their judgement, incorporating patient factors, when interpreting measurements of liver size . HepatomLiver parenchyma is usually characterized by a homogeneous echogenicity slightly more than the right kidney and slightly less than the spleen. An inhomogeneous parenchymal echotexture, without clearly defined focal lesions, may also be regularly encountered on US . Whilst Nodular regenerative hyperplasia is rare in pediatric patients and almost always diagnosed in association with an underlying disease such as lymphoproliferative and myeloproliferative syndromes, systemic lupus erythematosus (SLE) and the use of medication. NRH is represented by solitary but also, more often and typically, multiple isoechoic nodules. The CEUS pattern is unspecific with isoenhancement in all phases compared to adjacent liver parenchyma ,76,77.Liver elastography is a valuable complementary US technique, which should be used to further stage the degree of liver fibrosis in patients who may have clinical suspicion of chronic liver disease ,73,74,78When inhomogeneous liver parenchyma is identified, elastography is recommend in order to stage the grade of fibrosis and CEUS is recommended to improve the detection of any focal abnormalities . Follow-Epithelial, otherwise called simple liver cysts, are the most common incidental focal liver lesions. Cysts may be broadly categorized as congenital, epithelial cysts, pseudocysts, cystic masses secondary to infection/inflammation or cystic neoplasia. Cysts are observed in 5–20% of routine abdominal US examinations in the entire population ,83,84, wLiver cysts, as well as other cysts, are characteristically, on conventional B-mode US, round or ovoid, anechoic (echo free), smoothly delineated structures with refraction shadows at their edges, a strong posterior wall echo and post-cystic enhancement resulting from an intensity difference between the beam intensity deep to the cysts and in the cysts and no vascular flow signals on color Doppler imaging. Cysts displaying all these sonographic signs are defined as typical, whereas cysts showing only some of the signs are defined as atypical. Blood vessels mimicking a simple cyst have to be excluded by color Doppler techniques in order to rule out hereditary angiectasia, pseudoaneurysm and other arterioportal venous malformations, including hepatic manifestation of Osler’s disease.Typical (“simple”) cysts as an incidental finding do not require further investigation or follow-up. Symptomatic cysts should be further investigated together with those with atypical features, including internal echogenicity, mural nodules, multi-septation and septal calcifications. Absence of enhancement on CEUS is reassuring because it indicates that the cyst is an incidental benign finding. Worrisome features on CEUS include, most importantly, contrast enhancing solid mural nodule(s) and thickened contrast enhancing wall with irregular contour ,86,87. TThe evolution of hepatic and extrahepatic parasitic infections with, e.g., echinococcus granulosus (hydatid disease) and multilocularis has been recently described in detail and is valid for pediatric patients as well ,90,91,92In conclusion, follow-up is not usually required for incidentally detected liver cysts that are sonographically simple or cysts showing no enhancement on CEUS. CEUS allows prompt assessment of atypical cystic lesions at the time of diagnosis, with improved resolution compared to CT and the advantage of an immediate definitive diagnosis in comparison to contrast enhanced MRI, which needs further resources . MR imagSolid FLL are less common in children than in adults, are usually asymptomatic and present as IFs on imaging studies. Benign lesions are much more common than incidentally detected malignant lesions, depending on the age of the pediatric patients. Hemangiomas are the most common benign tumors of the liver.On US, FLL other than cysts can be divided into those that are hyperechoic in comparison to the surrounding liver parenchyma, isoechoic and hypoechoic. Most incidentally detected FLL are hyperechoic and represent hepatic hemangiomas which are usually solitary (but in one-third multiple), well defined and vascular or avascular in color Doppler examinations, depending on the age of the patient and, therefore, the respective hemangioma entity. Isoechoic FLL are typically hepatocellular adenoma and focal nodular hyperplasia. Hypoechoic FLL represent a wide variety of etiology. It is generally accepted that most hemangiomas in newborn are hypoechoic. It is a personal observation that within the first year the majority become hyperechoic. Conventional imaging with contrast agents has a limited ability to characterize FLL, and the appearances of benign and malignant masses frequently overlap.Analyzing the pretest probability and correlation with laboratory tests, clinical examination and previous imaging is the first action to be taken and is essential for accurate patient management. The second measurement is contrast-enhanced imaging. The liver is ideally suited for contrast-enhanced imaging such as CEUS due to its dual blood supply and high vascularity.The use of CEUS for identification and characterization of solid liver masses is recommended by guidelines ,93. CEUSMalignant liver lesions typically show variable arterial enhancement and parenchymal phase microbubble washout. Benign lesions typically either show no contrast enhancement in any phase or retain microbubbles in the late phase representing iso- or hyper-enhancement.Localized or multilocular (“starry sky”) liver calcifications are most often harmless and are almost invariably observed as IFs. Focal calcification may be seen as the result of post-inflammatory and often infectious (granulomatous) diseases or region-dependent parasitic bile duct infections. In some cases, the pathogenesis of the calcification remains uncertain. Calcification is characterized as hyperechoic structures which normally show acoustic shadowing distally owing to the reflection and attenuation of the ultrasound. Calcification of cysts are discussed above.Liver calcification without an associated mass does not require follow-up.Vascular tumors and vascular malformations are best categorized according to the 2018 International Society for the Study of Vascular Anomalies (ISSVA) classification, which incorporates the biology and genetics of vascular malformations in its nomenclature . The twoHepatic hemangiomas are the most common benign solid FLL in pediatric patients, and they are observed more often in girls than in boys ,83. The Most hemangiomas demonstrate typical sonomorphological features in conventional B-mode ultrasound and Doppler imaging. The conventional B-mode ultrasound criteria of typical hemangioma are as follows: less than 3 cm in diameter, next to a liver vein, hyperechoic in comparison to the surrounding liver parenchyma, homogeneous echogenicity, round or slightly oval shape, well-defined with a smooth outline, lobulated, feeding and draining vessels, absence of any signs of invasive growth, absence of any halo sign and posterior acoustic enhancement owing to blood filled capillaries.Although hemangiomas are highly vascularized masses, from a histopathological perspective, they essentially consist of a large number of capillary-sized vessels. Conventional color Doppler ultrasound often detects little or no blood flow inside the haemangioma due to slow flow. The supplying and draining vessels (“feeding vessels”) may be visualized (depending on the ultrasound system’s performance) at the edge of the lesion.CEUS features of hemangioma may be divided according to size and enhancement features into at least six types: The typical and small hemangioma, ≤30 mm, peripheral nodular contrast enhancement and complete or incomplete centripetal fill-in ,76,108. Infantile hepatic haemangiomas constitute vascular malformations. These can be focal, multifocal or diffuse, with the multifocal form being associated with cutaneous and other organ manifestations of hemangiomas. The Kasabach –Merritt syndrome (KMS) is an extreme form with life-threatening consumptive coagulopathy in the presence of a rapidly enlarging vascular tumor(s) of the liver. It usually presents in early infancy, but onset in the early neonatal period has been reported. The association with vincristine use has been described . HemangiImportant differential diagnosis with sometimes confusing contrast features includes peliosis  and otheHemangioma will only require treatment if the patient develops significant and long-term symptoms. Life-threatening syndromes require special pediatric knowledge and should be treated in specialized centers.Congenital hepatic hemangioma (CHH) is a rare vascular tumor that develops in utero. The tumor is present at birth, is typically largest at birth, and is usually diagnosed within six months of life. We refer to the published literature ,115,116.Infantile hepatic hemangiomas are vascular tumors that develop in the first weeks or months of life, although a small precursor lesion may be seen. Infantile hemangiomas characteristically have rapid growth within the first year of life followed by gradual involution over the course of several years, with a small amount of persistent fibrofatty tissue. Infantile hepatic hemangiomas are multiple or innumerable/diffuse and are associated with cutaneous infantile hemangiomas, which are histologically identical tumors with endothelial glucose transporter 1 (GLUT1) positivity immunohistochemically. Clinically, a patient may have complications related to vascular shunting, including high output heart failure and hypothyroidism, because these tumors express type 3-iodothyronine deiodinase . If treaCEUS may not be necessary for diagnosis when multiple or innumerable liver lesions are encountered at ultrasound in a patient with multiple cutaneous infantile hemangiomas. As grayscale imaging, infantile hemangiomas are typically more homogeneous in appearance than congenital hemangiomas. If a patient presents with liver lesions prior to identification of cutaneous infantile hemangiomas, the primary differential diagnosis consideration is liver metastases and CEUS is helpful for differentiation of the two entities. At CEUS, infantile hemangiomas typically have peripheral hyperenhancement with very rapid homogeneous centripetal fill-in . There iAs detailed above, hemangioma is a term used ubiquitously in the literature, but is a distinct, non-tumoral malformation, different from both congenital hemangioma and infantile hemangiomas . These lThe appearance at CEUS is similar to multiphase CT and MRI, with peripheral discontinuous nodular enhancement and expanding puddles of contrast material that fill-in from outward to inward. Fill-in is usually complete, but partial fill-in may be seen due to central clot or fibrosis. Most commonly, there is no contrast washout, although mild late washout has been reported. The presence of washout should not be mistaken for malignancy in these lesions if the characteristic arterial phase enhancement pattern is present .FNH is the second most frequently observed FLL in pediatric patients ,83,119 aSimilar to hemangioma, multiplicity has been reported in about one-third of patients and association with hemangioma is obvious ,123,124.FNH is typically an isoechoic or slightly hypoechoic compared with the surrounding liver parenchyma and hypervascular FLL of variable size, with age and size dependent regressive changes. FNH are difficult to detect if isoechoic  and if small .The vascular tree can be centrally located with centrifugal filling pattern (1), eccentric at the border of the lesion with respective filling pattern (2), with multiple supplying arteries at different sites (3) and without typical vessel architecture by imaging methods (4) . FNH in Parametric ultrasound techniques are helpful to illustrate the enhancement pattern ,127,128.The central scar is histologically present in only 70% of FNH  and, theFNH will only require treatment if there are significant and long-term symptoms .Hepatocellular adenoma is a benign neoplasm that more frequently occurs in females than males and is typically seen after the first decade of life. Understanding of these tumors continues to improve with increasing molecular and genetic knowledge. Adenomas are currently categorized into seven distinct subtypes: inflammatory; HNF-1subtypes ,135. ManHCA is a rare FLL. The relation of FNH/HCA can be estimated to be ten to twentyfold higher in children than HCA in adult patients. In pediatric patients, HCAs are relatively frequently seen in patients with glycogen storage disease (GSD 1). HCAs are also more commonly associated with diabetes mellitus and obesity (metabolic syndrome) in pediatric patients . Other iHistologically different subtypes of HCA have been described based on molecular (mutation present or not), pathologic features  and immunohistochemistry ,139,140.Hepatocyte nuclear factor 1a-inactivated HCA (most common according to Zucman-Rossi) .β-catenin-activated HCA, inflammatory HCA (steatotic or non-steatotic) and HCA with genetically determined underlying diseases, e.g., glycogen storage diseases are non-classified.There are no typical criteria in B-mode ultrasound. In a B-mode ultrasound of an otherwise normal liver, HCAs are roundish, well-circumscribed and usually isoechogenic with the surrounding liver tissue since HCAs are constituted by hepatocytes. Owing to this lack of echogenicity, HCA can be very difficult to differentiate from the surrounding liver tissue and small HCAs have been rarely described . In steaColor Doppler techniques can visualize increased peripherally predominant internal arterial hypervascularity ,83,125. The characteristic CEUS pattern of enhancement shows quick and intense homogenous peripherally predominant arterial phase hyperenhancement (APHE) and centripetal distribution. Teleangiectatic HCA may show more centrifugal enhancement patterns.® [® [Based on the exact histologic type of HA, washout can be typically observed ,137 and ®  or Sonaz® [®  are usedβ-catenin lesions demonstrating genetic overlap with HCC. In contrast, FNH can be managed conservatively in most patients. Small HCA might be closely followed up with the removal of potential precipitating factors. In doubtful cases, a multidisciplinary approach has been advocated [Differentiation is essential because of the different therapeutic approaches; HCA is an indication for surgery at least where growth has been demonstrated on serial imaging in HCA > 50 mm because of the risk of hemorrhage, rupture and potential malignant transformation due to dvocated .The molecular classification of HCA is of prognostic relevance; therefore, histological evaluation is mandatory. In pediatric patients, the underlying predisposition is also of importance. Biopsy specimens should be taken from the surrounding parenchyma as well in order to determine underlying diseases.Inflammatory hepatocellular adenoma  is the most common subtype and exposes the highest risk of spontaneous rupture, hemorrhage and necrosis in larger adenoma ,145,146.HNF-1tive use  and in ptive use . Treatmetive use ,145. HNFormation .At CEUS, HNF-1s common ,147,148. disease ,144,145. disease ,144.At CEUS, arterial phase hyperenhancement is typically diffuse and homogeneous, with either portal venous or delayed phase washout in almost 90% of lesions. Given overlap in appearance with HCC, biopsy may be necessary for diagnosis.Biliary microhamartomas  are ductal plate malformations characterized by very small cystic dilatations of peripherally located intrahepatic bile ducts lying within fibrous stroma. They may be single but are typically, and much more often, multiple. VMC may have different imaging appearances depending on their histopathology and size. Other cysts and cystadenoma have to be differentiated .The US appearance of VMC is specific with a coarse heterogenous appearance of the liver periphery, while innumerable micro-nodules (2–10 mm) of either decreased or increased echogenicity may be observed . High frCEUS findings have been reported in a few histologically proven patients with underlying malignant diseases with isoenhancement in the late phase using Levovist . The assMesenchymal hamartoma of the liver is a heterogenous, and often multi-cystic, mass typically seen in the first two years of life.In B-mode, ultrasound hamartomas may have different appearances depending on their histopathology and size. They may be single or multiple . Larger In most reported cases, hamartomas are small (less then 5 mm in diameter) hyperechoic lesions, some presenting the “comet tail” artefact ,152. SomThere is no consistent CEUS enhancement pattern. Some cystic parts of the lesions show no enhancement in either of the vascular phases due to their cystic composition, some show enhancement such as surrounding liver parenchyma, and occasionally some of them show bright and early enhancement in the arterial phase with a gradual decrease in intensity that is consistent with liver parenchyma ,151,155.Because of their non-specific image appearance, they can mimic a wide range of focal liver lesions from haemangiomas, cysts to metastases or HCC in cirrhotic liver.Cholangiocellular adenomas are frequently small neoplasia appearing as small solid hypoechoic nodules, typically in a subcapsular location ,156. TheToday, non-alcoholic fatty liver disease (NAFLD) is also commonly seen in the pediatric population and has been described as “epidemic obesity” ,157. FatIn the majority of patients with hepatic steatosis, distinctive hypoechoic areas in the liver hilum can be detected and should not be confused with a mass lesion. FFS typically shows centrally located feeding arterial vessels with less insulin and fat concentration, thus demonstrating the underlying pathological process of different vascularization of the liver hilum. The ultrasound-derived fat fraction (UDFF) is lower than in the surrounding steatosis and the stiffness measured by shear wave elastography is slightly higher ,68,69,75FFI can often be displayed in the liver hilum  and nextCEUS examination is “the” useful problem solving tool for the characterization of a focal fatty abnormality since it is prompt and readily available, thus demonstrating the underlying pathophysiological mechanism with demonstration of feeding vessels and almost identical arterial phase enhancement when compared with the surrounding liver parenchyma and no washout in the portal venous and late phases . CT and Inflammatory focal liver lesions are rarely asymptomatic and, therefore, rarely incidental findings. Phlegmonous infiltration and abscess formation will not be covered here. Autoimmune diseases typically show FLL in symptomatic patients. Examples include the inflammatory pseudotumor  and granMalignant focal liver lesions are rarely asymptomatic and, therefore, rarely incidental findings.The most common primary malignant tumor among children < five years is hepatoblastoma, and later (15–19 years old) hepatocellular carcinoma ,170,171.CEUS shows which pediatric patients needs further investigations by detecting washout in the portal venous and late phases. The further investigations include biopsy and histological examination, computed tomography (CT) for staging purposes and magnetic resonance imaging (MRI). Important laboratory biomarkers to support imaging have to be taken into account .Hepatoblastoma is by far the most common hepatic malignancy in children younger than five-years of age (90%)  and accoMuch more commonly, hepatoblastoma appears as a larger solid mass, often multilocular, that is size dependent with pseudocystic areas, necrosis and calcifications. The diagnosis is assisted by a typically marked increase in alpha-fetoprotein. The oncological staging methods are primarily computed tomography and magnetic resonance imaging . CEUS tyThe important differential diagnosis is hepatocellular carcinoma.In pediatric patients, HCC is strongly associated with underlying pathology and, therefore, most often not an incidental finding. Patients with vertical transmitted chronic viral hepatitis B, with or without liver cirrhosis and congenital metabolic disorders such as glycogen storage disease, tyrosinemia and longstanding hepatic vein obstruction ,175,176,The work-up for suspected HCC in liver cirrhosis has been described in detail, and the imaging criteria do not really differ in children compared to adults ,178,180.CEUS can also be used to characterize the very rare intrahepatic cholangiocarcinoma (ICC) in pediatric patients with specific diagnostic criteria being included in the CEUS LI-RADS classification system. The LR-M category for metastases and ICC in liver cirrhosis, including peripheral rim APHE, marked washout earlier than 60 s ,186,187.Primary sarcomas of the liver are very rare and most often large and symptomatic at time of diagnosis. Conventional imaging shows often palpable large and heterogeneous FLL due to intralesional hemorrhage, necrosis and cystic degeneration. In such FLL, e.g., embryonal sarcoma ,194,195,Primary hepatic lymphoma (PHL) is a very rare malignant tumor of liver, occurring in <0.1% of all non-Hodgkin’s lymphoma (NHL) ,199. DifHepatic metastases in general represent advanced disease and will rarely be found in a pediatric patient with no symptoms. The most common pediatric hepatic metastases originate from neuroblastoma or Wilm’s tumor. Metastases are often hyperenhancing in a diffuse  or rim pattern (if larger) in the arterial phase, with washout in portal venous phase in almost all patients ,45,83. CThe following issues are almost identical for the evaluation of IF in all organs and will be briefly summarized ,7,8,219.The effects of incidentally discovered pathological findings in a healthy individual can be unpredictable, complex and far-reaching, and may be underestimated by patients and clinicians ,224,225.Unnecessary further investigation and (over-)treatment may result in a potentially injurious and expensive cascade of tests and procedures, depending on specific health care organization insurance systems, e.g., Beveridge Model, Bismarck Model, NH Insurance Model, Out-of-pocket payments, et cetera ,233,234.IF may also require costly, potentially uncomfortable and sometimes invasive procedures to achieve a confident diagnosis, and can result in long-term follow-up. Further investigating an incidental finding should be organized in such a way that no pathology is missed, characterization is precise, but also the cost is kept to a balanced minimum, which is a general challenge for healthcare systems ,237,238.In conclusion, CEUS is an attractive alternative to CT and MR imaging and, most importantly, is accurate, avoiding radiation exposure and saving costs ,245,246.Most hemangiomas are “typical” and <30 mm and can be correctly identified by conventional B-mode and color Doppler imaging; further measures are not often necessary. Careful history-taking of symptoms, any underlying medical conditions or family history, and reviewing liver function tests, bilirubin and cholestasis indicating enzymes, are essential. The testing of tumor markers such as alpha-feto protein (AFP), carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA 19-9) is not generally recommended as a screening test.If there is any doubt CEUS can be promptly used as a problem-solving tool, we found that, in about 30% of patients, there will be an atypical criterion and at least in such cases contrast-enhanced imaging procedures should be used , depending on local protocols, availability and expertise. It should also be mentioned that hemangiomas in patients with fatty livers (hepatic steatosis) can appear to be isoechoic or hypoechoic when compared to hyperechoic parenchyma. Lesions suspected of being hemangiomas which show wash-out in the portal venous phase should be biopsied and histologically confirmed ,50. The The most commonly isoechogenic liver lesions are focal nodular hyperplasia and hepatocellular adenoma. Contrast-enhanced imaging and promptly available CEUS are required to exclude malignancy and to determine the diagnosis ,133,248.Malignant differential diagnoses must be excluded with a high degree of certainty, and this is only possible using contrast enhanced imaging techniques . WashoutThere are circumstances in which a CT or MR imaging examination may fail to adequately characterize a focal liver lesion, especially if this is incidentally found in a non-specifically protocolled examination. These include the detection of a liver lesion during a single-phase CT examination for trauma or when investigating the acute abdomen, excessive artifacts  degrading image quality in CT and MR IMAGING, suboptimal phase timing acquisition or small size that precludes confident characterization (particularly applicable in CT) ,48,49. IThe detection of an incidental FLL during US examination in pediatric patients is a common scenario but much rarer than in adult patients. Many factors need to be taken into consideration, in order to appropriately manage each individual patient and reach an accurate diagnosis. Firstly, carefully assess the pretest probability and, most importantly, include age , presentation of the patient, medical and family history , laboratory data and liver stiffness using elastography. Secondly, assess the lesion’s characteristics, including size and echogenicity. This combined approach highlights an important concept for the management of every incidentally found FLL by including all clinical information available and a multiparametric imaging approach. Pediatric patients should be subcategorized into no, low and high risk for clinical and imaging features. In addition, the psychological, healthcare and economic impact of every imaging modality should be taken into account for appropriate management, diagnosis and follow-up of these patients.An incidental finding (IF) during an imaging examination is the unintended and unexpected discovery of an abnormality that may be clinically significant (or not).The term IF can be used for any focal changes of the liver echogenicity and architecture that is causing no symptoms to the patient.Liver incidentalomas are frequently detected.Ultrasound is the primary and first-line imaging modality for the evaluation of liver pathology in children, including liver incidentalomas.Liver elastography should be applied in all patients with liver pathology to determine underlying risk constellation.Conventional B-mode ultrasound is accurate for the diagnosis of simple hepatic cysts, typical hemangiomas and hydatid cysts. As a result, such lesions could be followed up with US.Contrast-enhanced ultrasound (CEUS) is appropriate to precisely characterize solitary and multiple solid and cystic FLL with excellent accuracy in differentiating benign from malignant lesions.CEUS has an excellent safety profile.MRI is probably superior for the documentation of multiple lesions prior to surgery.Once characterization with CT/MRI has been initially performed, long-term follow-up can be undertaken with US/CEUS if necessary.Benign hepatic tumors are commonly observed in adults, but more rarely reported in children.The pretest probability—including presentation of the patient, past medical and family history with patient’s background risk of malignant and inflammatory liver disease , laboratory data and liver stiffness using elastography—and the lesion’s characteristics including size and echogenicity are taken into account for appropriate management, final diagnosis and follow-up of these patients.According to the factors mentioned, patients can be subcategorized into no, low and high risk for clinical and imaging features.The psychological, healthcare and economic impact of every imaging modality using a multiparametric imaging approach should be taken into account.In some patients, imaging will be inconclusive, and some form of tissue diagnosis will be required, either imaging-guided biopsy or surgical resection.In doubtful cases, a multi-disciplinary team (MDT) dedicated to liver diseases should be consulted.


The presence and extent of a cerebral perfusion deficit on either CT or MRI may play a role in clinical outcomes for patients with CVT, although future larger studies must be performed. This review presents a case-based overview focusing on the classic imaging characteristics of CVT and CVI in conjunction with bolus MRP and ASL findings in the adult population.Cerebral venous thrombosis (CVT) and cerebral venous infarcts (CVI) are diagnostic dilemmas secondary to their rarity, non-specific symptomatology at presentation, and variable imaging features. Despite its relatively infrequence, CVT is particularly prevalent in the younger adult population and is a potentially life-threatening disease with devastating neurological complications if not addressed in a timely manner. However, when treated promptly, CVT has the potential for a more reversible course and favorable prognosis than arterial ischemic strokes (AIS). The pathophysiology of CVI is distinct from that of AIS and is closely related to its potentially reversible nature. Familiarity with the conventional and variant venous anatomy, as well as the temporal evolution of imaging findings, is crucial in establishing diagnostic confidence. The use of MR perfusion imaging (MRP) and arterial spin-labeling (ASL) can potentially aid in the diagnosis of CVT/CVI  Cerebral venous infarct (CVI) is an uncommon cause of all strokes 0.5–2%) that disproportionately affects young adults , 2. CVI % that diThe clinical features, pathophysiology, diagnosis, and management of CVT and CVI are well-documented in the current literature. Ahmed et al. explored the normal cerebral venous anatomy and assessed the frequency of its anatomic variants . SaposniThe wide range of normal variant anatomy and collateralization in the cerebral venous system both influence and may confound the imaging diagnosis of CVT and CVI. Therefore, the purpose of this case review is to highlight CVI as a rare non-arterial form of stroke, which is an often-underdiagnosed entity in the adult population. In this overview, we outline the anatomy and pathophysiology of CVT and CVI and present a series of cases depicting the classic imaging findings of CVT and CVI using the most up-to-date diagnostic imaging techniques. We also emphasize the imaging appearance of CVT and CVI by anatomic location and chronicity of findings on computed tomography (CT) and magnetic resonance imaging (MRI). In particular, we provide updates to the current body of literature regarding the imaging appearance of CVT and CVI on MRI in conjunction with a case-based approach that highlights the imaging findings on perfusion sequences. To the best of our knowledge, there are no dedicated studies to date that explore perfusion with arterial spin-labeling (ASL) in CVI and with both bolus dynamic susceptibility contrast MR perfusion imaging (MRP) and ASL imaging in CVT and CVI. We hope that this overview heightens the reader's familiarity with CVT and CVI on conventional and perfusion imaging for daily clinical practice.While arterial ischemic strokes (AIS) are overwhelmingly seen in the older population, CVT/CVI is much more prevalent in young adults (particularly under 50 years of age and among women of childbearing age), affecting up to 3.7–5.3 times more female than male patients with minimal sex differences in age groups over 60 years , 4, 13. via superficial cortical veins, the anastomotic vein of Trolard (VT), and receives drainage from the emissary, meningeal, and calvarial diploic veins  intracranial hypertension, which may be isolated in up to 40% of patients with CVT; and (3) seizures  and unfractionated heparin (UFH)] in the management of CVT . Prompt orbidity . With imorbidity .Distinguishing CVI from AIS is clinically important as their treatment and prognosis differ. While AIS is more frequently encountered in the elderly population, CVI is overwhelmingly seen in the young adult population, particularly in women of child-bearing age given the female-related risk factors such as pregnancy, the postpartum state, and the use of oral contraceptives. The risk factors of CVI and AIS reflect their propensity for different populations. CVI have a much greater association with inflammatory and hypercoagulable states, as well as infection, particularly in the setting of CS thrombosis, whereas AIS most commonly affect those with atherosclerotic disease risk factors. AIS can arise from occlusion of an artery with subsequent ischemia of the downstream parenchymal distribution, with two-thirds of cases caused by thrombi and one-third by emboli, resulting in imaging findings within classic arterial distributions .While the classic clinical presentation of patients with AIS is hemiparesis or other focal neurologic deficits, the clinical presentation of CVI is more variable and non-specific with persistent and progressively worsening headache as the predominant symptom among seizures, ophthalmologic symptoms such as papilledema, encephalopathy, and even psychosis , 13. DeeThe treatment of AIS is dependent upon timely initiation of intravenous thrombolysis with tissue plasminogen activator (tPA) when appropriate, intra-arterial thrombolysis, and thrombectomy, as well as oral anticoagulation and antiplatelet medication. Despite the more frequent occurrence of parenchymal hemorrhage in CVI than in AIS, antithrombotic therapy with heparin and oral anticoagulants have shown mortality benefit in randomized controlled trials (RCTs) of LMWH and UFH with intravascular chemical and/or mechanical thrombolysis as an option when patients exhibit continued deterioration despite the initiation of anticoagulation , 4, 13.via venous dilation and recruitment of venous collaterals may still allow for adequate brain tissue perfusion at lower flow rates, at least early in the progression of venous occlusion , and contrast-enhanced MRV (C-MRV) . CompareThe imaging appearance of CVT varies based on the anatomic location of venous occlusion with thrombosis of the dural venous sinuses, superficial/cortical cerebral veins, and deep cerebral veins all possessing overlapping, as well as distinctive imaging findings. On unenhanced CT (NECT), the hyperattenuating vein or “cord sign” refers to the hyperdense appearance of a thrombosed vein and has a reported sensitivity ranging 25–64% . The thr* gradient echo (GRE) sequences and susceptibility weighted imaging (SWI) in acute CVT with gradual resolution over time  . In a reThe deep cerebral venous system drains the bilateral basal ganglia, thalami, and deep white matter. On NECT, dense appearance of the ICV or StS may look similar to a CECT . ParenchSince the CS receives venous drainage from the orbits, face, and neck, CS thrombosis has a much stronger association with infections of the face in addition to otomastoiditis, odontogenic disease, trauma, and neoplasm . On CT, Predictable changes in MRI signal abnormality with the stages of thrombus evolution form the basis for characterizing the chronicity of CVT. In the acute stage of CVT days 1–5), T1 isointense and strongly T2 hypointense clot, relative to brain parenchyma on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images, accompanied by absence of flow voids can be seen in the thrombosed vein or sinus, which reflects the desaturation of hemoglobin to deoxyhemoglobin within intact red blood cells , T1 isoi. An acut* sequences (During the subacute phase days 6–15), methemoglobin release from red blood cell lysis causes thrombus to appear hyperintense on T1, T2, FLAIR, and T2, methemoequences . During equences . Partialequences . In a reequences . CompletCVI may cross arterial distributions on imaging and manifest as subcortical and periventricular white matter edema with cortical sparing, which may be accompanied by parenchymal hemorrhages , 15. Whivia magnetic labeling of blood flowing into the brain  with worsening headache, dysarthria, acute right-sided weakness, and papilledema. On initial NECT, hyperdensity within the SSS and adjacent cortical veins was noted . InitialA 23-year-old male with history of ulcerative colitis presented at an outside hospital 2 days prior to arrival with headache, confusion, and agitation. Initial NECT showed bilateral frontal parasagittal hemorrhages  and associated filling defects on CTV . InitialA 43-year-old female presented with headaches, confusion, and left hemiparesis. Initial NECT shows curvilinear hyperdensity in the bilateral ICVs with right greater than left basal ganglia and thalamic edema . InitialA 57-year-old male with pituitary macroadenoma status post transsphenoidal resection and bifrontal craniotomy 1 week later for residual tumor removal, onset postoperatively with acute altered mental status. The normal preoperative NECT, T2, GRE, and DWI images are included for comparison , top rowA 26-year-old female with history of protein C deficiency, antithrombin III deficiency, and oral contraceptive use presented with difficulty reading and concentrating, as well as a left temporal headache. She was found to have non-fluent expressive and receptive aphasia on physical exam. Her NECT at presentation demonstrated acute left temporal hemorrhage with mild surrounding edema  and assume that the AIF is the sole blood supply of the region. The choice and measurement of AIF are a common source of error . For exaDespite the limitations of perfusion imaging, there is emerging evidence that CTP imaging may be helpful for prognostication of CVT as well as be practical in the emergent clinical setting due to its reproducibility and rapid scan times. Gupta et al. performed a prospective analysis of CTP imaging data from 20 patients with confirmed CVT before and after initiation of treatment for CVT . CBF wasCVI is a potentially life-threatening condition that has a more favorable prognosis if diagnosed earlier but is often underdiagnosed. AIS and CVI differ in important ways, including imaging characteristics, treatment, and prognosis. The imaging diagnosis of CVI is challenging in its varied and somewhat non-specific findings, compounded by generous variation in normal venous anatomy. This review provides a case-based overview of the classic imaging findings of CVT and CVI, as well as an exploration of the potential utility of perfusion imaging.AL and ET: manuscript writing, image acquisition, editing, and reviewing. VY: idea generation, manuscript writing, image acquisition, editing, and reviewing. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Intrahepatic cholangiocarcinoma (ICC) is a relatively rare subtype of cholangiocarcinoma, and there has been an increasing incidence of ICC in Western countries in recent years. Surgical resection is the most effective treatment for ICC. However, overall outcomes are extremely poor given that most patients are diagnosed at an advanced stage, and postoperative ICC recurrence is still very high despite hepatic resection. We report a case of metastatic ICC to the stomach presenting after resection of the original tumor, with imaging characteristics highly resembling gastrointestinal stromal tumor (GIST) on imaging. Reported cases of metastatic ICC to the liver are sparse. Given that there is a significant difference in the survival rate between metastatic cholangiocarcinoma and other tumors arising from the gastrointestinal tract, including GISTs, it is important to delineate the differences via imaging features. We further discuss the imaging characteristics of intrahepatic ICC, comparing and contrasting it to other gastric tumors. Metastasis of intrahepatic cholangiocarcinoma (ICC) is commonly found in the lungs, brain, skin, bones, and other organs but very rarely found in the stomach. There is a paucity of cases demonstrating gastric metastasis of ICC, with only five previously reported case reports found on PubMed. In four of the cases, gastric metastasis was found to exist concurrently with cholangiocarcinoma while evaluating for vague abdominal symptoms like epigastric pain and dysphagia ,2. ImamuWe report a rare case of metastatic ICC to the stomach that was discovered three years after initial surgical management, including cholecystectomy and left hepatectomy with caudate lobe resection for the primary tumor. On the surveillance CT imaging, the exophytic gastric mass was initially thought to resemble a gastrointestinal stromal tumor (GIST) given its both endo- and exophytic rounded configuration.This report and literature review highlight the imaging characteristics of ICC as well as other gastric tumors. By describing the radiologic findings in our case, we hope to increase awareness of this rare occurrence and explain the importance of it being on a radiologist’s differential diagnosis.A 63-year-old Caucasian woman presented with progressive pain in the upper abdomen for a few weeks after sustaining trauma to the abdomen. The initial contrast-enhanced CT scan of the abdomen and pelvis demonstrated a 7-cm hemorrhagic lesion in the left hepatic lobe, which was originally thought to be a ruptured hepatic adenoma Figure .MRI of the abdomen with and without contrast two days later revealed a 5.0 x 3.7 cm heterogeneous mass with some curvilinear enhancement in the caudate lobe of the liver. There were also moderate bilateral pleural effusions with overlying atelectasis and/or airspace disease Figure . A tissuDuring the surgery for a caudate lobe resection and cholecystectomy, the surgery was expanded to include a left hepatectomy due to the fact that her tumor was shown to be more extensive than originally believed. Pathology results were consistent with ICC. The patient subsequently completed adjuvant chemotherapy. Interval scans every six months were recommended for surveillance, which the patient adhered to up to two years from her original treatment. She was lost to follow-up for one year, but eventually returned to the clinic at which point her surveillance was re-initiated.Contrast-enhanced CT of the abdomen and pelvis performed at her re-initiation of surveillance demonstrated a 9.8 cm exophytic gastric mass along the greater curvature of the stomach, along with lymphadenopathy at the celiac station that was not present on imaging one year prior Figure . The patThe patient insisted on repeat CT imaging one month later before starting therapy. This examination showed a well-circumscribed lesion with heterogeneous enhancement on the arterial and venous phase images and central necrosis, with the appearance suggesting a gastrointestinal tumor Figure . Mass efEsophagogastroduodenoscopy (EGD), endoscopic ultrasound (EUS), and fine needle aspiration (FNA) were performed. On EGD, an approximately 10 mm mildly irregular and slightly raised mucosal patch was found on the duodenal sweep, and biopsies were taken. On EUS, three areas of concern for malignancy were identified. There was a large 105 mm x 60 mm heterogeneously mildly hyperechoic heterogeneous abdominal mass impressing upon the stomach from the outside and the gastric wall with a satellite lesion measuring 13.2 mm x 9.5 mm immediately adjacent to and contiguous with this mass. Within this lesion, there were areas of suspected necrosis. The lesion was inseparable from the gastric wall at EUS evaluation. There was a 21.8 mm x 19.9 mm hypoechoic malignant-appearing perihepatic mass adjacent to the proximal inferior vena cava. There was also an 18.1 mm x 12.6 mm mildly hyperechoic spherical mass lesion with a 3.7 mm pedicle that appeared to penetrate through the wall of the most cephalad portion of the inferior vena cava adjacent to the tricuspid valve. FNA of the large abdominal mass and perihepatic mass was performed, but FNA was not performed for the mass adjacent to the tricuspid valve, as it was a high-risk site and likely would not change the management of care. Pathology results indicate that both the large gastric and perihepatic masses obtained during EUS were positive for carcinoma cells and tissue fragments comparable with pancreaticobiliary ductal adenocarcinoma, reflecting metastatic cholangiocarcinoma.The patient felt grateful for the three years of life she has had since her initial diagnosis. Having witnessed her husband suffer from the effects of chemotherapy for several years, she ultimately decided to pursue hospice instead of further treatment for her metastatic disease.There is a paucity of cases demonstrating gastric metastasis of ICC, with only five previously reported case reports found on PubMed. In four of the cases, gastric metastasis was found to exist concurrently with cholangiocarcinoma while evaluating for vague abdominal symptoms like epigastric pain and dysphagia ,2. ImamuICC is a rare subtype of cholangiocarcinomas and makes up less than 10% of cholangiocarcinoma cases . ICC ariICC most often presents as a malignant mass lesion in a noncirrhotic liver. Specifically, contrast-enhanced cross-sectional imaging is helpful for differentiating ICC from hepatocellular carcinoma. Cholangiocarcinoma will have progressive contrast uptake throughout both arterial and venous phases because it is sclerosing, composed of fibrous tissue, and receives blood supply from the portal vein ,4,9. WhiIn our patient, it was difficult to distinguish gastric metastasis of cholangiocarcinoma from primary gastric cancer based on clinical and radiologic features. The large metastatic lesion found impressing on the gastric wall was initially thought to resemble a GIST due to its imaging characteristics. GISTs are often very large with areas of necrosis and cystic degeneration. On CT, these tumors have varying densities and show patchy enhancement after contrast is administered ,13. GISTIn addition to GISTs, there are mesenchymal tumors of the stomach that may appear very similar to ICC on imaging. For example, non-GIST sarcomas such as liposarcomas and leiomyosarcomas are large, aggressive tumors with heterogeneous enhancement and areas of necrosis . HistopaOther gastric neoplasms that are worth contrasting include gastric adenocarcinoma, gastric lymphoma, and gastric carcinoid tumors. Gastric adenocarcinoma is the most common gastric malignancy. On CT, adenocarcinomas have focal wall thickening with or without ulceration, polypoidal mass, or diffuse infiltration (termed linitis plastica) . GastricCross-sectional imaging of the chest and abdomen should be carefully assessed by a radiologist to guide treatment in patients with ICC. The extent of the tumor burden, presence of metastatic lesions, lymph node involvement, and vascular/lymphatic involvement should be evaluated to determine whether the patient is a surgical candidate. It is important to note that the probability of curative surgical resection is low and the median survival time by intention-to-treat analysis of surgical resectable lesions on imaging is 36 months . This isICC is a devastating disease with a very poor prognosis and poorly understood metastatic behavior. ICCs tend to recur despite apparent complete surgical resection and treatment, lending to their overall morbidity and mortality. Our case presents an instance of recurrence of ICC to the stomach, with the metastatic focus sharing very similar findings to a GIST. Additionally, other gastric tumors share similar imaging findings to ICCs and GISTs as well, including adenocarcinoma, lymphoma, and carcinoid tumors.It is important to appropriately recognize metastatic ICC and raise the possibility by the interpreting radiologist, including describing the extent of the tumor burden, presence of metastatic lesions, lymph node involvement, and vascular/lymphatic involvement to properly guide clinical management and help the primary providers determine whether the patient is a surgical candidate. Additionally, potential treatment modalities include endovascular therapy, such as chemoembolization. Early recognition of ICC can lead to hastening of therapy to allow more time to patients.


Although Meckel’s diverticulum (MD) is a relatively common asymptomatic gastrointestinal anomaly, an inverted MD is a rare entity that is challenging to diagnose prior to surgery and presents usually in the pediatric population with bleeding, anemia and abdominal pain. The most frequent adult presentation in non-inverted MD is intestinal obstruction, whereas bleeding and anemia are the most typical presenting complaints in inverted MD. Here, we report our experience with an adult female patient, who presented with 5 days duration of abdominal pain, nausea and vomiting. Imaging revealed signs of small bowel obstruction with bowel wall thickening in the terminal ileum and a double target appearance. This case describes a rare cause of adult intestinal intussusception because of inverted MD, which was successfully managed with surgery. The final pathology report confirms the diagnosis. Meckel’s diverticulum (MD) is the most common congenital anomaly of the intestines. It was first described by the German anatomist Johann Meckel in 1809 as an omphalomesenteric duct remnant . Hemorrh). Abdominal ultrasound showed bowel wall thickening in the ileum, a target-like mass containing a central area of increased echogenicity with a double target appearance. The initial diagnosis was a small bowel obstruction. Because of the severity of the abdominal pain, a decision to proceed with diagnostic laparotomy was made. Nasogastric decompression was done, IV fluids, antispasmodics and antibiotics were started. The patient underwent emergency surgery with a lower midline abdominal incision. Intraoperatively, an intussuscepted segment of the ileum measuring 8 cm in length located 75 cm from the ileocecal valve with dilated proximal ileal and jejunal loops was found and a soft polypoid shape mass was palpable within the lumen . Enterotomy was performed revealing a tubular segment measuring 6 × 2 × 0.8 cm with a globular swelling at the tip . No ischemic loop was identified. A diverticulectomy was performed in parallel with the longitudinal axon of the bowel lumen. Ectopic gastric mucosa was identified histologically confirming the diagnosis of inverted MD. The postoperative period was uneventful. CT scan with oral and IV contrast postoperative Day 5 showed no leak from the site of anastomosis (An 18-year-old female patient, with free past medical and surgical history, presented to the emergency department because of abdominal pain of 5-day duration associated with nausea, vomiting, constipation and loss of appetite. The pain was all over the abdomen mostly in the right lower quadrant, of gradual onset, colicky in nature, not radiated with any aggravating or relieving factors. It started intermittently and became continuous with increasing severity on the day of admission. On admission, she had normal vital signs. Physical examination showed a mildly distended abdomen with exaggerated bowel sounds. The patient had abdominal tenderness mostly in the right lower quadrant with abdominal guarding. Rovsing sign and rebound tenderness were both positive. However, the psoas and obturator signs were negative. No scars, hernias or masses were found. Laboratory tests are all within normal. A plain abdominal X-ray demonstrated air-fluid levels of the small bowel, with no pneumoperitoneum . Abdominhe lumen . Enterot the tip . No ischstomosis . The patMD occurs in 2% of the population . Up to 6The diagnosis and treatment of inverted MD is a subject of debate because of its rarity and the limited number of reported cases in the literature. Regardless of the cause, when the diagnosis of adult intussusception is made, surgical intervention is mandatory. This case report aims to alert surgeons to this rare clinical entity and discuss the various circumstances under which inverted MD is managed. We recommend that any similar case to ours gets reported, to expand the subsequent knowledge of this entity.N/A.Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editor-in-chief of this journal on request.None declared.The data used to support the findings of this study are included within the article.


Anisakiasis, a zoonotic disease that can lead to small intestine obstruction, has seen a significant rise in Spain. The country has become the first in Europe with an annual incidence of 8000 cases, primarily due to the popularity of consuming exotic dishes of undercooked or raw fish and the impact of climate change. The clinical presentation of anisakiasis can mimic symptoms of acute appendicitis or intestinal obstruction, leading to potential misdiagnosis. This case report describes a 37-year-old patient with no significant medical history who presented abdominal distension and intense pain in the right lower quadrant. The patient underwent surgery and received physiotherapy treatment, including therapeutic exercises and pulsed-pressure myofascial vacuum therapy, to facilitate functional recovery. The increasing incidence of anisakiasis in Spain underscores the need to consider it in the differential diagnosis of digestive diseases, given the high consumption of poorly prepared or raw fish in the region. Zoonosis is an infectious disease that can be transmitted between different species, including from animals to humans. Parasites are one of the causative agents of these diseases, and animals can act as vectors for their transmission. Fish, for instance, have been identified as one of the animal groups that can transmit parasites to humans . HoweverFurthermore, it is important to note that even though there may be a lower number of diagnosed cases, it does not diminish the potential severity and potential for fatal consequences. It is worth mentioning that, particularly in cases of parasitic nematodes, long-term control heavily relies on chemotherapeutic treatments. However, the prolonged use or incorrect dosage of these treatments can lead to the development of drug resistance ,3. DespiAnisakiasis, also known as anisakiosis, refers to the parasitic infection of humans exclusively caused by the third-stage larvae of the Anisakis simplex sensu lato parasite. It is important to distinguish anisakiasis from anisakidosis, which encompasses diseases caused by various members of the Anisakidae family . The larAnisakiasis is primarily contracted through the consumption of raw or undercooked fish that is infested with the larvae of this nematode ,8. AccorAfter the fish has died, the nematode larvae ensure their survival by migrating from the fish’s gastrointestinal tract to its muscle tissue and nearby organs . This unAmong the various methods employed for parasite inactivation, it is noteworthy to mention the use of pulsed electric fields, which have been widely utilized as a non-thermal approach to inactivate microorganisms present in liquid foods . This teThe symptoms are caused by two pathophysiological mechanisms: IGE-mediated immediate hypersensitivity allergic reaction and gastrointestinal inflammatory reaction. There are two clinical presentations based on the extent of penetration into the mucous membrane: the non-invasive luminal form  and the invasive gastrointestinal form , which is the more prevalent. The invasive form can be further classified into two distinct clinical presentations: gastroduodenal (65%) and intestinal  .The clinical manifestation of the intestinal form can sometimes lead to misleading suspicions of acute appendicitis or intestinal obstruction . IntestiWe present the case of a 37-year-old patient with no significant medical history who experienced abdominal distension for several days. In the last two days, the patient also developed acute and severe abdominal pain localized to the right lower quadrant without fever or vomiting. The patient lost consciousness; as a result, the patient sought medical attention at the emergency department, and emergency diagnostic tests were performed.During the abdominal examination, the abdomen was found to be soft and depressible. Superficial and deep palpation in the mesogastrium and right lower quadrant elicited pain. No signs of peritoneal irritation were observed. The laboratory analysis revealed only an elevated C-reactive protein level of 81 mg/L . The scan revealed the following observations: there was asymmetric mural thickening of the intestinal wall with submucosal edema, affecting a short segment of approximately 4 cm in length in the distal ileum located in the right lower quadrant  18,19].,19.18,19He presented a subocclusive picture with dilation of proximal bowel loops, as well as the presence of fluid and air-fluid levels inside. The patient presented a subocclusive condition characterized by dilation of the proximal bowel loops and the presence of fluid and air-fluid levels. These findings were accompanied by infiltration of the mesenteric fat, subcentimeter mesenteric lymphadenopathy, and a minimal amount of free fluid in the right parietocolic leak  19,20].,20.19,20The patient’s subocclusive presentation of the small intestine raised the possibility of tumor or inflammatory–infectious causes. An exploratory laparotomy was performed, which involved resecting the affected segment of the distal ileum, measuring approximately 10/15 cm in length, along with its mesentery. A mechanical side-to-side anastomosis was performed. The surgical intervention was justified by the possibility of the existence of lymphoma and, finally, due to the obstruction and ischemia of the intestinal segment ,20. The A new medical history was obtained from the patient, who reported frequent consumption of marinated raw fish in recent months. Following the surgical intervention, a physiotherapy treatment plan was implemented, which included kinesitherapy and therapeutic physical exercises during the hospital phase. The exercise regimen was continued in the outpatient phase, with the addition of the pulsed negative pressure procedure.® Vacuum Treatment device, specifically targeted scar tissue to prevent adhesions and myofascial retraction that could limit mobility .,20.18,20Additionally, it is worth noting that physiotherapy treatment plays a crucial role in achieving functional recovery following such a significant surgical intervention. Early mobilization programs have been shown to facilitate recovery after abdominal surgery ,25. ActiPrevious research on this subject coincides in pointing out the importance of exercise for therapeutic purposes to promote recovery after abdominal surgery ,28. In tAnisakiasis has significant clinical implications, and its increasing incidence in Spain, attributed to the high consumption of fish and the recent culinary trends of consuming it undercooked or raw, necessitates considering it as a potential diagnosis for digestive diseases. Due to the non-specific radiological findings associated with the intestinal form of the disease, it is advisable to include it in the differential diagnosis of inflammatory causes, with support from a thorough medical history. Surgical intervention plays a crucial role in the management of anisakiasis, and post-surgical physiotherapy treatment promotes the patient’s short- and long-term recovery, ultimately enhancing their overall quality of life.


Retroperitoneal leiomyosarcomas are rare tumors, mostly malignant. They are silent slow growing, and at the time of diagnosis, they are often of a considerable size. Management necessitates en bloc resection of the mass with adjacent organs, which is often challenging due to large size of the tumor. Herein, we present a case of 59-year-old male patient presenting for surgical management of 190 × 150 × 140 mm retroperitoneal leiomyosarcoma. Retroperitoneal leiomyosarcomas (RPL) are rare tumors of the mesenchymal cells originating from nerve, muscular or vascular tissues . It accoIt remains clinically silent given the anatomical adaptability of the retroperitoneum. It is often diagnosed incidentally, being asymptomatic, at a considerable size with close proximity to adjacent organs . The maiA 59-year-old male patient, known to have hypertension controlled by medication with no previous abdominal surgeries or any remarkable family history, presented with the complaint of a palpable indolent abdominal mass and vague abdominal fullness evolving for 4 months. The patient denied gross hematuria and lumbar pain. Clinical examination showed, on inspection, a visible large abdominal mass occupying the right hemiabdomen. The mass was hard and fixed to deeper layers. Neither jaundice nor dilated skin veins was found. Lab tests were normal. A thoraco-abdominal-pelvic computed tomography with contrast medium and delayed phases was performed. It showed a large right retroperitoneal solid mass measuring 190 × 140 × 120 mm with a thickened lobulated wall. It was heterogeneously enhancing, managing hypoattenuating areas, compatible with necrosis. It was responsible for anterior displacement of intestinal loops and pushed laterally the right colon. It crossed the midline displacing medially the inferior vena cava, abutting the abdominal aorta. Right mild hydronephrosis was found by direct invasion of the ureter. No clear dependence of any of the adjacent organ was identified. No metastatic lesions were found .Tumors markers  were normal.A scan-guided biopsy of the mass was realized. It was non-contributory showing necrotic tissue without specific cells.Surgery was performed by a midline xipho-pubic incision. The tumor was occupying the entire abdominal cavity, involving right lumbar ureter, and terminal ileum. Meticulous dissection was done and the mass was freed from adherences. After confirming the resectability of the tumor, we realized complete resection of the mass, a 20-centimeter invaded ileum loop with right kidney and ureter. Immediate ilio-ileal anastomosis was realized. No vascular repair was needed. Operative specimens weighted 16 kilograms . PatientHistopathological examination of operative specimens showed focal areas of necrosis accounting for less than 50% of the tumor mass. Tumor cells were spindle shaped, pleomorphic and had moderate to severe atypia. Mitotic figures were abundant, counting 1–2 mitosis per 10 CFG. Surgical margins were free of disease. Renal parenchyma, renal pelvis and ureter were free of neoplasia. Pathology turned out to be RPL Grade II according to the French staging system for sarcoma tumors FNLCC .The patient’s case was discussed at the tumor board. The decision was, due to negative surgical margin, that the patient should be followed by clinical and radiological exams, without adjuvant chemotherapy or radiotherapy. On 1-year follow-up, the patient is disease free with no complaint.RPL are slow growing tumors, diagnosed incidentally in asymptomatic patients or with nonspecific symptoms , usuallyComplete resection of RPL with intact capsule is the cornerstone of the management of this entity. En bloc resection of tumor with adjacent organ resection, most commonly the kidney and colon, is frequently needed to achieve complete resection . It is tVarious types of chemotherapeutic agents, such as anthracycline-based chemotherapy: Doxorubicin, have been utilized over the years in an attempt to increase survival. It has not demonstrated to increase survival neither provide a better quality of life . PreoperThe potential benefit of neoadjuvant radiation includes decreasing tumor size, improving resectability, and improving local control. No studies have definitely demonstrated a benefit to preoperative radiation for RPL . Some stSimilar to chemotherapy, no randomized controlled trials of adjuvant radiotherapy have been published, but many clinicians advocate the use of radiotherapy in patients found to have positive margins. Patients who were given doses of radiation between 53 and 56.4 Gray after undergoing surgical resection with varying results. Preoperative radiation is a category 2B recommendation of the NCCN, for tumors at high risk for local recurrence [In patients undergoing an R0 resection, postoperative radiotherapy should be given to patients with high-grade tumors, extremely large tumors, and those with close margins. After an R1 resection, the NCCN recommends postoperative radiotherapy if neoadjuvant therapy was not given and a boost of 10–16 Gy if preoperative radiotherapy was given . In caseIt is often more complicated. Multiple studies have also shown that the metastatic progression of the disease is associated with significantly lower rates for complete resection (70%). In case of unresectability, radiation therapy  or systemic therapy can be proposed .RPL is a rare tumor, mostly malignant. The best therapeutic option remains the complete surgical resection with negative microscopic margins, often challenging. A multidisciplinary approach is highly advocated to improve overall survival rate.


Urorectal septum malformation sequence (URSMS) is characterized by incomplete partitioning of the genital, rectal, and urinary tracts, resulting in a severe form of anorectal malformation. The partial URSMS, also known as the persistent cloaca, represents a milder variant where a single perineal opening serves as a passage for the urinary, gastrointestinal, and reproductive tracts.We present a rare case of partial URSMS accompanied by duplicated vagina and uterus, hydronephrosis, ascites, and anal atresia.This case report describes the sonographic findings at different stages of pregnancy and their changes throughout gestation. Urorectal Septum Malformation Sequence (URSMS) is a series of congenital abnormalities resulting from a migration/fusion disorder of the urorectal septum and maldevelopment of the cloacal membrane. It is characterized by the absence of perineal and anal openings, ambiguous vulvar sex, abnormalities in urinary and genital structures, colon malformations, lumbosacral, and other abnormalities . It is aIn our case, positive findings were observed on ultrasonography from 12 weeks of gestation, and these findings progressively worsened as gestational weeks advanced. Before delivery, the case was diagnosed as “anal atresia,“ “meconium peritonitis,“ and “hydronephrosis.“ However, after birth, it was confirmed as a case of partial URSMS. This paper aims to analyze the ultrasound manifestations and characteristics of the patient throughout pregnancy to enhance understanding of partial URSMS and improve the rate of prenatal diagnosis.A 38-year-old pregnant patient, gravida 2, para 1, was directed to our Prenatal Diagnosis Center at 12 weeks of gestation due to suspicion of an abdominal cystic mass in the fetus. Apart from one previous normal vaginal delivery, the patient’s obstetric history was unexceptional. The diagnosis of gestational diabetes was made following a glucose tolerance test conducted around the 24th week of gestation. After diabetes management during pregnancy, her blood sugar was well controlled. Moreover, there was no reported family history of congenital anomalies. The mother reported no exposure to teratogenic substances. The Serologic test for TORCH  infections revealed a negative result.Grayscale fetal ultrasonography (US) revealed an anechoic, unilocular, sausage-shaped mass in the mid-abdomen, lying anterior to the left kidney Fig. a, measurAt 23 + weeks of gestation, the fetal ultrasound displayed that the echogenic bowel was still present and mild dissociation of the left renal pelvis Fig. a, b, witOn one day of birth, intestinal adhesiolysis and transverse colostomy were performed. Subsequently, laparoscopic anoplasty, urethroplasty, and then stoma closure were completed. She is undergoing regular check-ups at our Departments of Pediatric Surgery and Urology. The child, who is 2.7 years old, has normal defecation and no incontinence.Various names have been used in the literature to refer to URSMS, including the cloacal dysgenesis sequence , persistAt present, the pathogenesis and inheritance mechanism of URSMS remains unclear. In this case, the expectant mother had not been diagnosed with conditions other than gestational diabetes mellitus. Though previous studies have reported that high blood glucose levels during early pregnancy are associated with an increased risk of various birth defects , case reEscobar et al.  speculatThe external genitalia of the URSMS fetus are often indistinct and difficult to distinguish, and most female fetuses are associated with double vaginal and double uterine malformations . In caseIn our case, an abdominal cyst was presented at 12 weeks gestation and resolved at 15 weeks. We hypothesized that it was probably formed by intestinal dilation. The reasons behind the early-stage dilation and its subsequent appearance as echogenic bowel at 15 weeks remain uncertain. The visibility of dilated bowel contents during the first trimester could be potentially attributed to ingesting amniotic fluid . AdditioDiagnosing partial URSMS through prenatal ultrasound commonly involves identifying several characteristic findings, including an abdominal/pelvic cystic mass, hydronephrosis, oligohydramnios, distended bowel/bowel obstruction, and ascites. The diagnosis is typically considered when two or three adjacent cysts are visualized in the female fetal pelvis, corresponding to the bladder and the vagina, with the latter often exhibiting septation , 17. AlmURSMS represents the most severe type of anorectal malformation; therefore, early and accurate diagnosis is crucial for providing subsequent prenatal counseling and ensuring families are well-prepared for the perinatal journey. If a fetal abdominal cyst is detected between 11 and 14 weeks of gestation, the possibility of anorectal malformation should be considered. Serial ultrasound assessments provide significant advantages in monitoring the evolving abnormalities during gestation, enabling the gradual recognition of characteristics associated with the cloacal anomaly during fetal development.


External iliac arterial dissection after robot‐assisted laparoscopic procedures is an extremely rare complication. It may cause severe adverse outcomes, such as lower limb necrosis.A 73‐year‐old man was diagnosed with cT2 ≤ N0M0 bladder cancer and underwent robot‐assisted radical cystectomy. After surgery, he complained of severe left lower leg pain. Computed tomography showed external iliac arterial occlusion. Furthermore, the emergency operation revealed external iliac arterial dissection and occlusion.The robot arm does not have any sense of force or touch. Thus, it is necessary to pay sufficient attention to the traction of blood vessels and contact with major organs. CTcomputed tomographyDVTdeep vein thrombosisRARCrobot‐assisted radical cystectomyExternal iliac artery dissection is a rare and serious complication in robotic surgery, but early treatment can prevent lower extremity ischemia.Robot‐assisted laparoscopic surgery has been performed in various fields, not only in urology. As a major advantage, it allows the performance of delicate procedures using robotic arms. However, because the surgeon has no sense of touch, he/she may unknowingly cause damage to surrounding organs. Moreover, external iliac arterial dissection after robot‐assisted laparoscopic procedures is an extremely rare complication. It often results in critical limb ischemia, requiring emergency surgery. To the best of our knowledge, no study has reported external iliac arterial dissection after robot‐assisted laparoscopic surgery. Here, we describe a case of external iliac arterial dissection after RARC with an intracorporeal ileal conduit urinary diversion and extended pelvic lymphadenectomy.A 73‐year‐old man was admitted to our hospital for macroscopic hematuria. Cystoscopy revealed a nodular tumor filling the right wall of the bladder. He underwent transurethral resection of the bladder cancer and was diagnosed with urothelial carcinoma, high grade, and pT2≤. CT did not detect obvious lymph node swelling and distant metastasis. Moreover, he underwent RARC with an intracorporeal ileal conduit urinary diversion and extended pelvic lymphadenectomy after three cycles of neoadjuvant chemotherapy with gemcitabine and cisplatin. The total operative and console times were 754 and 546 min, respectively. The amount of blood loss was approximately 225 mL. After returning to the hospital room from the operating room, he complained of severe pain in the left lower leg. Pulseless of the dorsal pedal artery, pallor, paresthesia, and motor paralysis were not observed. We suspected compartment syndrome owing to the prolonged lithotomy position and consulted an orthopedist. He was diagnosed with compartment syndrome and underwent an emergency fasciotomy of the left lower leg. However, the skin coloration and pain in his left lower leg did not improve. Pulseless of the dorsal pedal artery and pallor were observed the next day. Paresthesia and motor paralysis were not observed. CT revealed an external iliac arterial dissection and thrombotic occlusion Fig. . We consExternal iliac arterial dissection is a rare complication of RARC with an intracorporeal ileal conduit urinary diversion and extended pelvic lymphadenectomy. To the best of our knowledge, no similar previous case has been reported. The major vascular complications of robotic surgery are DVT and compartment syndrome. However, their frequencies are very low, with 0.5–0.6% and 0.03–0.3%, respectively.When a blunt external force is applied to an artery, damage occurs to the less elastic intima, causing arterial dissection.Vascular occlusion caused by traumatic iliac artery deviation differs from chronic diseases, such as atherosclerosis obliterans due to poorly developed collateral blood vessels. Therefore, ischemic symptoms in the lower limbs are progressive, and delay in diagnosis and treatment can cause lower limb necrosis, making it difficult to save the limbs.Asymptomatic cases are treated conservatively. However, in the case of severe symptoms of lower limb ischemia due to arterial occlusion, it is necessary to take the dynamic CT as soon as possible.We assumed that the patient had compartment syndrome since he had lower limb pain after prolonged surgery in the head‐down lithotripsy position. If findings suggest arterial occlusion, contrast‐enhanced CT should be immediately performed after the visual examination of the entire lower limb and palpation of each artery, not just the lower leg. If a diagnosis of serious vascular occlusion due to arterial deviation is made, as in this case, prompt surgery is essential.The robot arm does not have any sense of force or touch. Therefore, it is necessary to pay sufficient attention to the traction of blood vessels and contact with major organs.We presented our experience of a rare case of external iliac arterial dissection after RARC. External iliac arterial dissection after RARC is an extremely rare complication, however, may lead to serious adverse outcomes, such as lower limb necrosis. Thus, the traction of blood vessels and contact with major organs by the robot arms should be avoided as much as possible.Syunsuke Nakashima: Writing – original draft. Shinro Hata: Writing – review and editing. Mayuka Shinohara: Data curation. Tadasuke Ando: Visualization.Toshitaka Shin: Writing – review and editing. Hiromitsu Mimata: Conceptualization.The authors declare no conflict of interest.Not applicable.Not applicable.Not applicable.


Although liposarcoma is the most prevalent soft tissue sarcoma in adults, head and neck liposarcomas are rare and account for less than 5% of all liposarcomas. The primary orbital location is even more exceptional, with fewer than 100 cases documented in the medical literature. Given the scarcity of cases of orbital liposarcoma and the limited familiarity of physicians and pathologists with this pathology, there is an increased risk of non-diagnosis or misdiagnosis, which may lead to inappropriate patient management. To address these challenges, we present a case of primary orbital myxoid liposarcoma and subsequently discuss the primary findings of this case based on the evidence documented in the medical literature. This comprehensive text is designed to serve as a valuable resource for healthcare professionals and pathologists, with the goal of promoting both clinical suspicion and accurate diagnosis and treatment of this rare condition in future cases. Liposarcomas are malignant tumors of adipocytic differentiation and represent one of the most prevalent subtypes of soft tissue sarcomas, constituting about 15% to 20% of all cases. This condition is categorically divided into four primary subtypes: well-differentiated liposarcoma , dedifferentiated liposarcoma (DDLPS), myxoid liposarcoma (MLPS) and pleomorphic liposarcoma ,7,8,9. TA 33-year-old male patient sought medical attention after experiencing two months of painless proptosis and swelling in the right upper eyelid A. At theHistological analysis revealed a malignant mesenchymal neoplasm of adipose origin A. This nFurthermore, the lesion had a network of branching blood vessels and showed apparent CD-57 expression F.Via reverse transcription-polymerase chain reaction (RT-PCR) , we Based on these findings, the diagnosis of primary orbital myxoid liposarcoma was established. The initial medical recommendation for the patient was exenteration, but the patient chose to decline this procedure. However, given the presence of malignant cells at the margins of the initial surgical resection, a subsequent anterior orbitotomy became imperative to widen and ensure clear surgical margins. During this second intervention, the surgical margins were confirmed to be free of malignant cells. After postoperative recovery, the patient underwent adjuvant radiotherapy. The surgical site received a dose of 64 Gy by intensity-modulated radiation therapy (IMRT). At the last follow-up, performed three years after surgery, the patient is still alive with no signs of recurrence.Although liposarcoma is the most common soft tissue sarcoma in adulthood , it is eOrbital liposarcoma usually manifests as a painless proptosis ,5,6,7,8,Myxoid liposarcoma is distinguished by recurrent translocations, mainly t12;16) q13;p11) and, less frequently, t , which result in fusion of FUS or EWSR1 with DDIT3, respectively [ and, les q13;p11)Because of the high recurrence rate and some resistance to radiotherapy and chemotherapy, surgery remains the primary approach to treat most orbital liposarcomas, with the possibility of removing adjacent tissues such as the eyelids, lateral crus and orbital wall to ensure complete eradication of the tumor ,5,6,7,8.Orbital liposarcoma is an uncommon form of cancer that, due to its rarity, often receives limited attention from medical professionals and pathologists. This relative obscurity may increase the likelihood of misdiagnosis and consequently lead to inadequate clinical management affecting the patient’s prognosis. Besides conventional light microscopy and standard staining techniques, confirmation of the diagnosis usually requires immunohistological studies and, in some cases, more complex tests may be warranted. The main treatment option is usually exenteration of the eye, although this decision is understandably challenging for the patient. Furthermore, radiation therapy may be considered as part of the treatment plan. Recurrence is a common concern, underscoring the importance of close and vigilant patient follow-up.


Prader-Willi syndrome (PWS) is a genetic disorder involving multiple systems, with an incidence of about 1/10000–25000. Ovarian torsion (OT) is not commonly found in children. Ovarian cyst acts as one of the primary factors resulting in OT. While ovarian cyst torsion with Prader-Willi Syndrome has not been reported before.2. The patient manifested the special facial features, an obese body, with the abdomen distended into a spherical shape. The fat accumulation in the abdomen significantly embarrassed the palpation. The abdominal CT scan indicated a huge cystic mass in the abdominal cavity, sized about 138 mm × 118 mm. According to medical history, the patient was born with low crying and hypotonia, who has developed the uncontrollable eating behavior since 3-years old. These abnormalities led to a speculation of PWS syndrome, so a genetic test was performed and finally confirmed it, concluding a torsion of ovarian cyst with PWS. With the multidisciplinary consultation, a careful treatment strategy containing the control of blood pressure and blood sugar, coenzyme Q10 was administrated to nourish the myocardium and the application of Growth Hormone was developed. All the above preoperative treatments have brought great benefits to patients. Thus promising the successful completion of operation. The postoperative follow-up till now indicated that the abdominal incision was well healed, without operative complications.A 12-years old female was admitted to Emergency Department of our hospital with the chief complaint of abdominal pain. The outcomes of physical examination revealed the height of 150 cm, weight of 103 kg, BMI of 45.77 kg/mThis may be the first case report. In the treatment of ovarian cyst torsion, PWS syndrome requires fully consideration, as the latter can lead to multisystem abnormalities, especially the relation to perioperative management, and even fatalities. Genetic testing should be conducted early when PWS was suspected, accompanied with adequate preparation for the perioperative period, the follow-ups of patients should be maintained for a long time after surgery. Ovarian torsion (OT) refers to a series of pathophysiology in which the ovary and fallopian tube twist along the vascular pedicle of pelvic infundibular ligament and ovarian proper ligament, which leads to the obstruction of ovarian arteriovenous and lymphatic reflux and perfusion obstruction. The incidence of OT is about 5/100,000 in childhood, which requires emergency surgical intervention in general . TherefoPWS was first proposed by three pediatric doctors in 1956 . AccordiMultiple systems throughout the body are covered by the clinical manifestations of PWS, which are complex and diverse, and lack of specificity, accompanied with the typical age characteristics. Although PWS is poor in the overall prognosis, it leads to a relatively low fatality rate, about 3% , generalOvarian cyst torsion combined with PWS is rather rarely reported. PWS will lead to the abnormalities of endocrine system, and ovarian cysts are also closely related to hormone secretion. Despite the unclear specific relationship between them, both require high consideration in the treatment. We checked the relevant literature and found that this maybe the first case up to now.A 12-years old female was admitted to our hospital with the complaint of abdominal pain. The patient has developed abdominal pain two days before admission, manifesting as intermittent lower abdominal pain, which were aggravated when the body position was changed, without other accompanying discomfort. One day ago, the patient felt the abdominal pain was worsened, so she turned to Emergency Department of our hospital.By inquiring the patient's medical history, we acquired that she was born with low crying and hypotonia. Unfortunately, this phenomenon did not attract enough attention by doctors and parents at the time, so no examination or treatment was performed on the patient. The patient has also exhibited the delayed development, who learned to sit alone at 1-year old, and started to walk at 2-years old. Since the age of 3-years, she displayed an uncontrollable appetite, accompanied with the significantly increased weight. These abnormal performances have also not attracted sufficient attention from parents. The menarche occurred when she was 11-years old, with a regular period about once every 30 days, and lasting 2–3 day each time. There reported no history of dysmenorrhea, and the time of the last menstrual period could not be accurately described.2, obesity, abnormal facial appearance, disordered behavior, obstructive sleep apnea, soft abdominal muscles, a spherical shape of the distended abdomen. The fat accumulation in the abdomen significantly embarrassed the palpation. Mild tenderness was reported in the right lower abdomen near the pelvic cavity, without rebound pain, abnormal vulvar shape, sparse pubic hair.The results of physical examination were, body temperature: 38 °C, heart rate: 109 beats/min, breathing: 24 times/min, blood pressure: 130/94 mmHg, height: 150 cm, weight: 103 kg, BMI: 45.77 kg/m9/L, CRP: 224.04 mg/L, Hb1Ac12.9%, BG13.64 mmol/L, Urine-Test: UG 4 + , MAU > 344 mg/L. The results of abdominal ultrasound: a liquid dark area was identified in the right appendage area, about 138 × 118 mm in size, with clear boundary and transparent internal space, the left ovary was normal, without obvious abnormality in the left appendage area. Results of CT-scan: 1. Right lower abdomen to pelvic cavity occupied by cystic space 2. Stone formation in appendicular fecal 3. Intestinal effusion in lower abdomen 4. Multiple small lymph nodes at the root of mesenteric  for respiratory management, the tracheal intubation was withdrawn at that night and the patient returned to the general ward the next day. Eating was started on the first day after the operation and PWS treatment was continued accompanied with Guidance of diet and exercise, control of blood pressure and blood sugar. Coenzyme Q10 was continued to nourish myocardium and Growth Hormone was used regularly.2, accompanied with the satisfactory blood pressure and blood sugar control, and outpatient review is regularly carried out (Fig. After 7 days, the patient was cured and discharged, followed by the postoperative follow-up till now. According to the present outcomes, the patient has a good recovery, which is mainly revealed by two aspects. First, the surgical recovery is considerable, with the beautiful abdominal scar, without signs of recurrence indicated by the abdominal CT, or occurrence of surgical complications. Second, for PWS, guidance endocrinology and nutrition is continued to be received by the patient, the weight control is currently satisfactory, the BMI index dropped significantly to 38.67 kg/mThe clinical manifestations of PWS are complex, also differing in region and ethnicity. Therefore, the diagnostic level also varies among different countries and regions . At presEspecially in remote and poor areas, most patients will not be diagnosed and treated until obesity occurs, while the relatively late treatment results in a low overall quality of life. The occurrence of this situation is generally resulted by the lack of understanding of clinicians in various regions or the improper selection of genetic testing methods. Therefore, the enrichment of awareness of PWS and punctual diagnose and intervene can effectively modify its overall treatment effect and prognosis. The case reported here is a typical example of a lag in diagnosis due to the insufficient awareness. In fact, in the appearance of symptoms with hypotonia and feeding difficulties in the neonatal period, the existence of PWS should be considered by clinicians.Genetic testing required for PWS diagnose includes : chromosIn terms of the treatment of PWS, considering the involvement of the abnormal performance of multiple systems throughout the body, a comprehensive management model covering multidisciplinary participation is recommended, mainly referring to the treatment of metabolic abnormalities, such as dietary behavior intervention and nutritional management, sex hormone replacement therapy, growth hormone and other endocrine problems . Some scTherefore, a strict food manage is recommended with the participation of doctors and parents, so as to ensure a regular diet and a reasonable nutritional structure. At the same time, an appropriate exercise plan should also be formulated to help patients control weight efficiently.Surgery is currently adopted as the gold standard for the diagnosis of ovarian torsion, which can achieve to determine the degree of torsion and determine tissue activity, in which the timing of surgery is rather critical .Auxiliary examination can further contribute to the diagnosis of mass. However, due to the low specificity of clinical manifestations, an accurate diagnosis is still difficult to achieve. Ovarian cysts act as one of the essential factors leading to ovarian torsion. Prepubertal hormone secretion disorders and Ovulation dysfunction during puberty can induce the occurrence of ovarian cysts. According to the current literature, the relation between menstrual cramps and ovarian torsion still remains uncertain.Most scholars hold that ovarian torsion is more commonly found after menstruation, accounting for 84% of the total, believing that it is associated to the increased incidence of ovarian cysts after menstruation , 16.In addition, the diameter of ovarian masses is also associated to OT. As the literature reports, OT should be alerted for people with a diameter of ≥ 5.5 cm . The casIn summary, it may be the first case report of PWS combined with ovarian cyst torsion. The diagnosis of PWS was so delayed for the patient and the opportunity for early intervention and treatment were missed. Therefore, we hope that the case here will highlight the importance of early diagnosis of PWS. Obesity and endocrine abnormalities are considered one of the common causes of ovarian cysts, as well as the common clinical symptoms of PWS patients. During the treatment of ovarian cyst torsion, the characteristics of PWS should be taken into consideration. Genetic testing should be carried out punctually, the advantages of multidisciplinary consultation should be fully utilized, as well as adequate preparation for the perioperative period, the concept of rapid recovery medicine should be adhered to, accompanied with a minimally invasive surgery, so as to avoid the occurrence of unplanned secondary operations as far as possible. As ovarian cysts still have a certain probability of recurrence, and the treatment of PWS is a long-term process, the follow-up of patients requires to be lasted for a long time after surgery.