Retroperitoneal fibrosis (RF) is a rare disease, which can be primary (idiopathic) or secondary. We present the case of a 56-year-old patient with symptomatic RF, in whom, after ineffective treatment with glucocorticoids, immunosuppressants, and non-steroidal anti-inflammatory drugs for one year and a progressive clinical course, a follicular lymphoma in the retroperitoneal space and several lymphoma nodes was identified. We also include a literature review on differential diagnosis through image inspection and case reports of lymphoma mimicking RF. Retroperitoneal fibrosis (RF), a rare disease characterized by progressive inflammatory, fibrous mass in the retroperitoneal space, was first described in 1905. Nowadays, more than a hundred years later, the diagnosis of this disease is not difficult, but due to the variety of etiologies and the unclear pathogenesis, further differential diagnosis is very important for RF patients, especially the need to determine the malignancy of retroperitoneal mass. It may require repeated judgments throughout the whole course of the disease.A 56-year-old woman with headache, back pain, nausea, and new-onset hypertension presented to the emergency in January 2016. She did not have a remarkable medical and family history. Blood testing revealed normal blood cells and renal, pancreatic, and liver functions. The kidney ultrasound revealed a dilation of the left renal pelvis. Then contrast-enhanced computed tomography (CT) scan of the abdomen and pelvis showed soft tissue in the retroperitoneum, which invaded the nearby small intestine and surrounded the bilateral ureters, and caused bilateral hydronephrosis. These findings were suggestive of retroperitoneal fibrosis. She was admitted to rheumatology. The rheumatologist did not find any other possible etiologic factors except a positive anti-SSA antibody, so she was diagnosed with idiopathic RF (IRF). She received treatment with methyl prednisone 32mg per day, tamoxifen 10mg twice a day, and methotrexate 10mg per week for one year. However, a repeat CT scan of the abdomen and pelvis in March 2017 revealed no changes（Figure In December 2018, the patient went to the hospital because of bloating, coughing, and wheezing for one month. A positron emission tomography (PET)/CT scan showed that the soft tissue with fluorodeoxyglucose (FDG) hypermetabolism was located in the nearby abdominal aorta, vena cava, and small intestine mesenteric and presacral area. The maximum standardized uptake value (SUVmax) of it was 13.45（Figure She underwent a biopsy of a cervical lymph node and a puncture of the lesion in the retroperitoneum region. The pathology results demonstrated the lesion was follicular lymphoma (grade 1-2). The immunohistochemical results revealed a lymphoid infiltrate composed predominantly of CD20-positive medium-size B lymphocytes that were CD10, BCL2, BCL6 positive, and Ki67 15%-positive, without normal lymphoid follicles Figure .2/day 0, vindesine 4mg/day 1, epirubicin 75mg/m2/day 1, prednisone 100mg/day 1-5, cyclophosphamide 0.75g/day 1). She obtained complete remission after six cycles of chemotherapy. In addition, she received rituximab therapy every two months at 375 mg/m2 plus lenalidomide at 25mg/day for two years after the chemotherapy. The last follow-up was in February 2022, and she remained in complete remission status.She received six cycles of R-CHOP (rituximab-cyclophosphamide-hydroxydaunorubicin-Oncovin-prednisone)-28 chemotherapy (rituximab at 375 mg/mRF is a rare disease that can occur at any age. The incidence rate is only one in a million. RF may be idiopathic or secondary, and benign or malignant, as a fibrous, inflammatory soft tissue that stretches in the retroperitoneum, encompassing the aorta and vena cava, and extending along the iliac vessels to the pelvis. The fibrosis often progresses later to encompass the ureters and be responsible for ureterohydronephrosis. Reliable classification of RF is often not possible. Peisen et al. concluded that RF may be a consequence of, or a coexisting condition with, arterial vascular disease, an autoimmune disease, vasculitis, IgG4-associated RF based on IgG4-positive plasma cell infiltrates, drug-induced RF, RF resulting from radiation or surgery, and malignant RF . In 75% In our case, the patient first went to the hospital because of headache, back pain, nausea, and new-onset hypertension, and the CT examination showed a mass in the retroperitoneum that surrounded the adjacent iliac vessels and the urinary tract. It demonstrated a diagnosis of RF. The rheumatologist, who found the patient’s morphological manifestation consistent with IRF, diagnosed her after a complete differentiation except for a biopsy of the lesion, and treated her with methyl prednisone, tamoxifen, and methotrexate. Indeed, some authors presented criteria for a malignant cause of RF by morphological examinations . In a reFinally, we searched eight cases reports of lymphoma mimicking RF in PubMed, which included two cases of B-cell Non-Hodgkin lymphoma ,8, threeIn addition to the common inducing factors, we should be more alert to RF secondary to malignant tumors, such as lymphoma. With the development of imaging technology, PET-CT examination may important for the early detection of malignant tumors. It is important for early diagnosis and prognosis to obtain histopathology by puncture or surgery at the same time.


A 36-year-old woman with Ehlers-Danlos syndrome (EDS) presents with a painful and enlarging right lower extremity mass prompting imaging work up. Herein we present a case report of an uncommon complication and a unique treatment option of a large right anterior tibial artery pseudoaneurysm caused by repetitive microtrauma in a patient with EDS and a congenital club foot. Ehlers-Danlos syndrome (EDS) is a connective tissue disorder characterized as impaired collagen metabolism, predominantly involving joints, skin, and blood vessel wall . EDS canThe differential diagnosis for an enlarging lower extremity mass or swelling is broad, but includes muscle spasm or herniation, deep venous thrombosis, edema or hematoma. However, soft tissue tumors such as liposarcoma, angiosarcoma, and undifferentiated pleomorphic sarcomas should also be considered. This case report summarizes the clinical and imaging work-up of a young woman presenting with a painful, palpable mass of the right lower extremity.A 36-year-old female patient presented with an enlarging right lower extremity that was tender and had a reported palpable mass on the anterolateral aspect of the right calf. Pertinent past medical history includes EDS (type unknown), spontaneous colon perforations, and right clubfoot deformity corrected with a rigid lower leg brace. She denies a history of trauma to this region, and has not experienced fever, chills, weight loss or previous episodes of spontaneous hemorrhage or bleeding.On physical examination, the palpable abnormality is located adjacent to the contact site of the splint she wears for the club foot deformity that provides static dorsiflexion assistance and lateral stability for the entire foot-ankle area.Contrast-enhanced magnetic resonance imaging (MRI) of the right lower extremity demonstrated a 3.9-cm pseudoaneurysm (PSA) in the anterior compartment with pulsation artifact and surrounding hematoma measuring up to 13.9 cm (Figure An ultrasound-guided biopsy was performed of the nodular soft tissue to exclude an underlying neoplasm. Pathology demonstrated an acute inflammatory process and small fragment of reactive bone without evidence of malignancy.Given the concern for a PSA in this patient, a computed tomography angiogram of the abdomen and pelvis with lower extremity run off Figure  was perfThe patient was referred to Interventional Radiology for embolization of the PSA once malignancy was excluded. Surgical management was deferred as the patient was only given the option for amputation and was told that there was a high risk of poor wound healing following surgery. As an alternative to amputation, endovascular embolization was offered.The endovascular embolization was performed through direct access into the anterior tibial PSA and a bidirectional embolization of the anterior tibial artery. Proximal and distal anterior tibial artery embolization occurred through retrograde and antegrade manipulation. This approach was opted to avoid potential complications from manipulations of non-target vessels in this patient with multiple additional aneurysms in the right lower extremity attributed to the patient’s EDS. No coils were placed in the pseudoaneurysm to avoid a large coil mass which causes late complications. Stagnant contrast was noted in PSA at the end of the procedure Figure . SurveilThe clinical evaluation and workup of a patient with EDS who presents with a painful lower extremity mass in the absence of trauma or clinical evidence of blood loss can be difficult. However, a degree of suspicion is warranted as spontaneous lower extremity pseudoaneurysm has been reported in the literature . VasculaOf the 13 variants, only four types can be confirmed by laboratory tests. This makes the classification of EDS a challenge in most cases . In a prWhen present, a pulsation artifact centered at the pseudoaneurysm can be a helpful clue on MRI. This is especially important as the degree of surrounding soft tissue enhancement and abnormal signal may lead to a broadened differential diagnosis, including a soft tissue mass, as demonstrated in the present case .Due to vessel fragility, both surgical and endovascular procedures should be handled with care in this patient population. The rate of complications for endovascular procedures was found to be as low as 2% in a single-institution retrospective study . ComparaWorkup of a palpable swelling in an EDS patient should include vascular pathology as well as soft tissue malignancies. Given vessel fragility, endovascular versus surgical approaches to correct vascular abnormalities in patients with EDS should be weighed against the risk of causing additional complications.


The thrIn very rare situations, patients with MPN can develop osteolytic lesions , 20, 21.2The MPN program at the Princess Margaret Cancer Centre is the largest MPN program in Canada. The MPN program has surveyed 1096 MPN patients regarding their symptoms, 208 MPN patients reported experiencing bone pain. Among these 208 patients, 17% have PV, 15% have ET, and 50% have MF . Of 208 patients, 76 (37%) reported moderate or higher levels of bone pain (5/10 or greater based on the MPN‐symptoms survey).2.1JAK2 V617F mutation, erythropoietin level was < 2 IU/L, and bone marrow biopsy demonstrated a hypercellular marrow with increased erythropoiesis and granulopoiesis, establishing a diagnosis of PV. The patient was started on aspirin 81 mg daily with phlebotomies as needed. In 2020, she developed excruciating right hip pain, leading to multiple emergency department presentations. Magnetic resonance imaging (MRI) of right hip demonstrated T1 hypointense and T2 hyperintense signal in the right intertrochanteric region extending into the right greater trochanter measuring 3.9 × 3.5 × 2.6 cm  scan confirmed the right femur lesion with increased metabolic activity, but found no other abnormalities. Subsequent CT‐guided biopsy of the right proximal femur reported hematopoietic tissue with hypercellularity and panmyelosis consistent with PV.In 2019, a 59‐year‐old woman was found on routine bloodwork to have elevated hemoglobin (185 g/L) and hematocrit (0.58). All other counts were within normal limits. Molecular testing confirmed m Figure . ComputeCoinciding with the osteolytic lesion the patient lost phlebotomy requirements . A repeat bone marrow biopsy had no significant changes from prior assessment Table . She rep3We conducted an English literature search using Google scholar, PubMed, and Medline, for studies, reviews, case series, and case reports of patients with diagnosis of PV, ET, PMF, and MPN‐unclassified associated with osteolytic bone lesion from 1970 to July 2021.In total, 16 case reports were found, highlighting that osteolytic lesion secondary to MPNs is rare  along with the presence of osteolytic lesions; though diagnostic procedures were often delayed until further symptoms or cytopenias developed , 20, 21.44.1The etiology of osteolytic lesions in MPN is not fully understood. Activation of the JAK‐STAT pathway leads to altered hematopoiesis and proliferation of one or more cell lines, associated with modifications to the microenvironment of the bone marrow , 22, 23.4.2The occurrence of osteolytic lesion in MPN patients, independent of another malignant process, is rare. The summarized experience from the literature raises the concern that osteolytic lesions are a sign of disease progression and denote a poorer prognosis , 20, 21.Reported medical and surgical therapies have demonstrated some temporary symptomatic benefit, though most patients have persistent or new lesions. Radiographic resolution of osteolytic lesions has only been reported in two of the 16 cases. One case had resolution following allogeneic stem cell transplant . BucelliBased on the 16 case reports, and our institute's experience, the occurrence of osteolytic lesion in MPN patients is rare. However, the occurrence of osteolytic lesions is associated with significant bone pain, declined quality of life, aggressively behaving disease, an increased risk of disease progression or leukemic transformation, and limited survival , 20, 21.4.3The presence of persistent worsening bone pain in patients with MPN should prompt imaging with CT scan followed by PET scan as needed to investigate for lytic lesions, especially with the poor prognosis associated with this finding. Given that osteolytic lesions can occur in other hematological malignancies , ruling out concurrent disease is necessary  , 14, 17.5We report the first case of chronic‐phase PV with osteolytic lesion with clinical response to ruxolitinib. The occurrence of osteolytic lesions in MPN is rare and characterized by excruciating bone pain, aggressively behaving disease, and may indicate an overall poor prognosis. Further investigation and attention to bone pain with MPN is warranted to reduce symptom burden and identify patients at higher risk of progression.Funding support for this project from the Corresponding author Hassan Sibai.Dawn Maze has research support, honoraria, advisory board, and consultancy for Novartis, Celgene/Bristol‐Myers Squibb, PharmaEssentia, Takeda, and Pfizer. The other authors have no conflict of interest to disclose.Written consent for the publication of a case report was obtained from the patient. In addition, Institutional Ethic Review was not required for case report by the University Health Network.Supporting InformationClick here for additional data file.


We aimed to prospectively compare the diagnostic performance of gadoxetic acid-enhanced MRI (EOB-MRI) and contrast-enhanced Computed Tomography (CECT) for hepatocellular carcinoma (HCC) detection and liver transplant (LT) eligibility assessment in cirrhotic patients with explant histopathology correlation.In this prospective, single-institution ethics-approved study, 101 cirrhotic patients were enrolled consecutively from the pre-LT clinic with written informed consent. Patients underwent CECT and EOB-MRI alternately every 3 months until LT or study exclusion. Two blinded radiologists independently scored hepatic lesions on CECT and EOB-MRI utilizing the liver imaging reporting and data system (LI-RADS) version 2018. Liver explant histopathology was the reference standard. Pre-LT eligibility accuracies with EOB-MRI and CECT as per Milan criteria (MC) were assessed in reference to post-LT explant histopathology. Lesion-level and patient-level statistical analyses were performed.p <  0.001) but lower specificity  compared to CECT. EOB-MRI had a sensitivity twice that of CECT  when all HCC identified at explant histopathology were included in the analysis instead of imaging visible lesions only. Disregarding the hepatobiliary phase resulted in a significant drop in EOB-MRI performance . EOB-MRI had significantly lower pooled sensitivity and specificity versus CECT in the LR5 category with lesion size < 2 cm . EOB-MRI had higher sensitivity  compared to CECT for detecting < 2 cm viable HCC in treated lesions. Accuracies of LT eligibility assessment were comparable between EOB-MRI  and CECT .Sixty patients  underwent LT successfully. One hundred four non-treated HCC and 42 viable HCC in previously treated HCC were identified at explant histopathology. For LR-4/5 category lesions, EOB-MRI had a higher pooled sensitivity (86.7% versus 75.3%, EOB-MRI had superior sensitivity for HCC detection; however, with lower specificity compared to CECT in LR4/5 category lesions while it was inferior to CECT in the LR5 category under 2 cm. The accuracy for LT eligibility assessment based on MC was not significantly different between EOB-MRI and CECT.NCT03342677, Registered: November 17, 2017.ClinicalTrials.gov Identifier: The online version contains supplementary material available at 10.1186/s40644-023-00532-3. Gadoxetic acid-enhanced Liver MRI had better diagnostic performance in some categories compared to Computed Tomography for the diagnosis of Hepatocellular carcinoma in patients with liver cirrhosis enlisted for transplantation.Gadoxetic acid-enhanced liver MRI had a significantly superior ‘real world’ or true sensitivity for hepatocellular carcinoma diagnosis versus computed tomography.Liver transplantation eligibility assessment was not significantly different between gadoxetic acid-enhanced liver MRI and computed tomography.Liver transplantation (LT) is the treatment of choice for patients with hepatocellular carcinoma (HCC) confined to the liver who are not eligible for partial hepatic resection or ablation, while palliative therapies such as transarterial chemoembolization (TACE), radiotherapy, and systemic agents are recommended for those with more advanced disease . AccordiPreoperative imaging is relied upon not only for HCC detection but also for the determination of LT eligibility . While dTo date, limited studies have prospectively compared the diagnostic performance of CECT and MRI for detection of HCC in LT candidates –9, with Thus, we aimed to prospectively compare the diagnostic performance of EOB-MRI and CECT for HCC detection and transplant eligibility in pre-LT cirrhotic patients with explant histopathology correlation.This was a prospective, single-institution HIPAA compliant, and ethics-approved study. Between November 2017 and April 2021, written informed consent was obtained from consecutive patients following chart review in a pre-transplant clinic. Inclusion criteria were: (a) liver cirrhosis enlisted for LT with a high probability of undergoing transplantation within 12 months, and (b) diagnosed, suspected and or treated HCC with priority MELD points based on cancer diagnosis. The exclusion criteria were patient age < 18 years, low Glomerular filtration rate (GFR) (< 30 mL/min/1.73 m2), high bilirubin (> 3 mg/dl), pregnancy, MRI contraindications (pacemaker etc.), prior systemic HCC treatment, bridging therapies (TACE or ablation) between imaging and LT or removal from the LT waiting list. Patients underwent CECT and EOB-MRI alternately every 3 months until LT. Among 101 enrolled patients, the final cohort comprised 60 patients with exclusion of 41 patients  with a standardized multiphasic liver protocol , and a LI-RADS treatment response (LR-TR) category was assigned as viable, nonviable, equivocal or nonevaluable  . CompletA study investigator (ABJ) correlated the recorded observations on EOB-MRI and CECT with those on explant pathology reports based on lesion size and segment location. Lesions were matched if the difference between the pathologically and radiologically measured sizes was less than 10 mm, and no similar-sized lesion was observed in the same segment. Cholangiocarcinoma and mixed HCC-cholangiocarcinoma tumors were analyzed as non-HCC tumors. HCCs detected only on histopathology without corresponding LR-4 or 5 imaging observations in the same segment location were regarded as false-negative (FN), and the contrary was defined as false-positive (FP).Prospective LT allocation was determined as per Extended Toronto criteria (ETC), which offers LT irrespective of HCC size or number but requires no macrovascular invasion, extrahepatic disease, systemic cancer-related symptoms, or poorly differentiated tumors . Thus, wp-value < 0.05 was considered statistically significant. Interobserver agreement was assessed via concordance rate (%) of diagnosis between the readers for EOB-MRI and CT. Reader-level scores were compared using McNemar tests. The sensitivity and corresponding 95% confidence intervals (CIs) of EOB-MRI and CECT in detecting HCC in correlation with the reference standard in pooled-reader analyses using a generalized estimating equations approach as previously described were calculated [The diagnostic performance of EOB-MRI and CECT was compared for each reader based on a lesion-by-lesion level analysis of histopathologically confirmed HCC. Two lesion level analyses were performed: (i) wherein only the imaging detected lesions matched with corresponding histopathology correlation were included and (ii) wherein all lesions detected on histopathology irrespective of imaging visibility were included with the HCCs not detected on imaging being categorized as false negatives (FN). A lculated . The perOne hundred seventeen non-treated liver lesions  and 134  treated observations were recorded in 60 liver explants. Table Non-treated lesionsLR-4/5 score as HCCWithout size consideration, HCC detection sensitivity and accuracy were higher for both readers with EOB-MRI versus CECT. The pooled sensitivity was significantly greater with EOB-MRI Fig. , while tLR-5 score as HCCRegardless of size, the sensitivity and accuracy were higher with CECT compared to EOB-MRI for both readers. However, pooled sensitivity with CECT was not-significantly higher than EOB-MRI. The pooled specificity of CECT was again not-significantly greater than EOB-MRI. For HCC size of 1–1.9 cm, a statistically significant lower pooled sensitivity was observed for EOB-MRI vs CECT with a statistically significant higher pooled specificity with CECT. For HCC ≥ 2 cm, the pooled sensitivities were not significantly different, and specificities were equivalent.LR-3 scoreAll LR-3 lesions scored by both readers on EOB-MRI and CECT proved to be HCCs at explant histopathology, hence were considered false negative in our analysis. Reader 1 scored fewer LR-3 lesions on EOB-MRI versus CECT , with similar occurrences for reader 2 . The final diagnosis of LR-2 and LR-3 lesions is summarized in Additional file Added value of HBPp <  0.001), whereas the specificity remained unchanged (84.6%). The disregard of HBP signal specifically impacted the HCC <  2 cm with a significant drop in pooled sensitivity  while specificity (77.8%) remained unchanged ns Table The ‘real-world’ or true sensitivity for HCC detection as per LR-4/5 score was significantly superior with EOB-MRI versus CECT for both readers, regardless of HCC size, and the pooled sensitivity of EOB-MRI (65.9%) was more than twice that of CECT (32.2%).Treated observationsForty-two viable HCCs were identified in 134 treated observations on histopathology. Regardless of size, EOB-MRI had a marginally higher true sensitivity versus CECT utilizing LI-RADS TRA; however, the differences were statistically insignificant.p = 0.156; CT: p = 0.158). However, both readers showed lower accuracies with CECT and EOB-MRI in detection of patients exceeding versus those meeting MC in reference to histopathology . Both readers obtained higher accuracy (with both CECT and EOB-MRI) in predicting patients exceeding MC with HCC diagnosis as per LI-RADS scoring compared to OPTN criteria (p = 0.06)  of patients would have been eligible for LT based on MC  for all observations with a corresponding histopathologic abnormality. CECT had greater interobserver agreement than EOB-MRI for categorizing LR-4/5 . For LR-TR categorization, the interobserver agreement was substantial for EOB-MRI  and CECT . Interobserver agreement for determination of LT eligibility was moderate for LI-RADS .Our study demonstrated that EOB-MRI had an overall superior sensitivity but lower specificity compared to CECT for HCC diagnosis in non-treated LR-4/5 lesions referenced against explant histopathology. EOB-MRI was superior to CECT on analysis by size (< 2 cm versus > 2 cm), although without statistical significance. In the LR-5 category, although EOB-MRI and CECT had statistically similar pooled diagnostic performance without consideration of HCC size, EOB-MRI was inferior to CECT in the < 2 cm subgroup. HCC detection sensitivity and specificity with CECT and EOB-MRI have wide reported variability in the LR-4/5 and LR-5 categories defined by LI-RADSv2018 , 23–25. Evaluation of whole-liver explant parenchyma has the merit of detecting HCC invisible on imaging, thereby getting truer imaging sensitivity estimates. The ‘real world’ or true sensitivities of EOB-MRI and CECT in LR-4/5 categories were lower in our study when analyses included all HCC diagnosed at explant histopathology irrespective of a corresponding imaging observation. A prior meta-analysis and a recent study have reported lower sensitivities of EOB-MRI in studies wherein liver explant was the only reference standard , 26 in lHBP signal as an AF for adjusting LI-RADS category significantly improved EOB-MRI sensitivity in LR-4/5 observations in this study, regardless of size and for < 2 cm group, without significant impact on specificity. A prior retrospective study reported no significant differences between CECT and EOB-MRI for HCC diagnosis with LR-4/5 and LR-5 categories . HoweverIn our study, EOB-MRI was superior to CECT for detection of < 2 cm viable HCC in treated lesions as per LI-RADS TRA. However, without size consideration, there were no significant differences between the two modalities like in some prior studies , 34. A pIn this study, EOB-MRI and CECT had equivalent performances for assessing simulated LT eligibility based on MC with LI-RADSv2018 and OPTN criteria in reference to explant histopathology, even as lower accuracies were observed in prediction of patients exceeding MC. Although recent studies have demonstrated moderate to high accuracy for determining LT eligibility based on MC using CECT and EOB-MRI with LI-RADSv2018 and OPTN, however in these retrospective studies , 38, patWe must acknowledge some limitations of this study. This was a single-center study with a limited patient cohort; however, all patients were enrolled prospectively, and explant histopathology correlation was available for the entire study cohort. The lack of using threshold growth in this study for assignment of LI-RADS categories may have underestimated the sensitivity for HCC diagnosis but is applicable to both modalities. The mean time interval between CECT and LT was 1 month longer than the time between EOB-MRI and LT, which could have led to changes in HCC characteristics, thereby impacting imaging evaluation variably between CECT and EOB-MRI. We acknowledge that the three-month interval may change tumor size for aggressive HCC, and it would be ideal to have both CECT and EOB-MRI performed closely before LT. However, since we could not predict the exact timepoint of LT, it was not feasible to perform both EOB-MRI and CECT at every 3-month follow-up interval. It can be challenging to precisely match every lesion recorded on imaging to the liver explant, particularly with small lesion size and because of the shrinkage effects of formalin fixation. Lastly, since we used CPN or non-CPN at histopathologic examination as the reference standard for viable HCC in treated lesions, microscopically viable HCC could have led to underestimation of LR-TR viable category.EOB-MRI has superior diagnostic performance for HCC diagnosis in pre-LT cirrhotic patients over CECT in specific categories, while it was inferior to CECT for LR-5 observations less than 2 cm. While both EOB-MRI and CECT have a lower diagnostic performance in a real-world scenario, EOB-MRI outperforms CECT therein. At a patient level, LT eligibility assessment appears to be comparable between EOB-MRI and CECT; however, both modalities have relatively lower accuracies for identifying patients exceeding MC compared to those within MC.Additional file 1. Multiphasic Liver CT protocol (Aquilion 64).Additional file 2. MRI Protocol for Gadoxetic acid-enhanced liver MRI (EOB-MRI).Additional file 3. LI-RADS v2018 – Major and Ancillary Features with EOB-MRI.Additional file 4. Lesion characteristics evaluated on EOB-MRI.Additional file 5. Lesion characteristics evaluated on Contrast-enhanced CT scan.Additional file 6. CECT and EOB-MRI treatment response categories.Additional file 7. OPTN classification system for lesions seen on imaging of cirrhotic livers.Additional file 8. Distribution of non-treated hepatocellular carcinoma (HCC) and viable HCC in explants.Additional file 9. Histopathology results for LR-2 and LR-3 lesions scored by readers on EOB-MRI and CECT.


Introduction. Osteoid osteoma is a benign osseous tumor characterized by an excessive formation of unmineralized bone matrix. The aim of this study was to present, through a case report, the clinical and radiological manifestations of osteoid osteoma affecting the left basilar border of the mandible. Observation. A 30-year-old male patient presented with left mandibular pain of unknown etiology. The chief complaint was mandibular pain accentuating mainly at night, originating in the left basilar border, and radiating to the whole mandibular hemi-arch. Extraoral examination revealed a small, bone-consistent, and slightly painful swelling. Computed tomography scan revealed a well-limited, infracentimetric, and mixed osteolytic image with central nidus and peripheral osteocondensation. Histological examination revealed osteoid osteoma. Surgical excision of the lesion was performed, and the pain stopped immediately. Discussion. This benign tumor presents many clinical and radiological features similar to other lesions. To differentiate osteoid osteoma from these other bone pathoses, practitioners should have a clear concept and keen observation skills. Confrontation of the clinical, radiological, and anatomopathological data is therefore essential to establish the correct diagnosis and to determine the appropriate treatment plan. Condensing images of the jaw bones represent a heterogeneous group of lesions with several possible diagnoses. Some are specific to the jaws, whereas others can be found throughout the skeleton.Osteoid osteoma is a benign bone tumor, with prevalence in the jaws accounting for less than 1%. This entity accounts for 3% of all primary bone tumors and 10% of benign bone tumors . OsteoidThis benign bone tumor is characterized by an excessive formation of unmineralized bone matrix, called osteoid. It has a small, oval, or round centrally located area, called nidus, composed of osteoid and trabeculae of newly formed bone, deposited within highly vascularized connective tissues and surrounded by reactive sclerotic cortices. This tumor has a limited growth potential reaching a maximum size of just 1–2 cm .The true nature of this lesion is still unknown. It is considered as a low growth neoplasm or an inactive neoplasm by some authors and as the consequence of a trauma or an inflammatory process by others .Lack of knowledge concerning the etiopathogenesis of this tumor and its confusion with similar bone lesions, such as odontogenic lesions, make its diagnosis difficult . FurtherProper diagnosis and a well-established treatment plan are fundamental because of the specificity and scarcity of this tumor. Diagnosis is greatly made based on the clinical features and radiological imaging, and it is confirmed by the histopathological examination. Confrontation of the clinical, radiological, and anatomopathological data is, therefore, essential to make the correct diagnosis and to subsequently establish the appropriate treatment plan.The aim of this study was to present, through a case report, the clinical and radiological manifestations of osteoid osteoma affecting the left basilar border of the mandible.A 30-year-old male patient, in good general condition, was referred by his treating dentist to the Department of Oral Medicine and Surgery for left mandibular pain of unknown etiology.The patient's chief complaint was mandibular pain originating in the left basilar border and radiating to the whole mandibular hemi-arch. He had undergone endodontic treatment on the left mandibular second molar (tooth #37). On extraoral examination, a small, bone-consistent, and slightly painful swelling was noted on palpation of the left basilar border. The patient reported that the pain accentuated mainly at night. No labiomental hypoesthesia was noted, and the rest of the extraoral examination was normal. Intraoral examination revealed the presence of a temporary coronal filling on the left mandibular second molar (tooth #37). Axial and transverse percussions were painless. No swelling was noted on palpation of the vestibular bottom.Panoramic radiograph was performed . It showThe patient was asked to consult his treating dentist for oral cavity rehabilitation and further endodontic treatment on tooth #37. However, the treating dentist opted for the extraction of the tooth, as it could have been the cause of the pain. Yet, no improvement was noted by the patient after the extraction of the tooth #37. Retroalveolar radiograph was then performed . It demoComputed tomography (CT) scan Figures  and 3 waFaced with this clinical presentation involving nocturnal pain and a well-limited, infracentimetric, and mixed osteolytic image with nidus and peripheral osteocondensation, diagnosis of benign osteogenic tumor of osteoid osteoma type was made.The patient was operated under general anesthesia using exobuccal approach. An incision over the left mandibular basilar border and full-thickness flap detachment was made to provide direct access to the lesion. Curettage and esthetic sutures were then performed. The anatomopathological examination confirmed the diagnosis of osteoid osteoma. Indeed, this revealed irregular bony trabeculae lined with osteoblasts. The bony trabeculae showed varying degrees of calcification. The stroma was fibrocellular and strongly vascularized.The patient consulted after 15 days for sutures removal. The one-month check-up revealed good healing of the wound. The outcome was favorable, and the pain disappeared.First described by Jaffe in 1935, osteoid osteoma is a benign osteoblastic tumor, not related to an infectious phenomenon. It frequently develops in long bones, but it very rarely occurs in the head and neck . A revieThe aforementioned articles were published between 1951 and 2020. The small number of published clinical cases could be due mainly to the rarity of these lesions in the craniofacial region and the difficulty of diagnosing this benign tumor.Correct diagnosis of this tumor requires clinical and radiological investigation. The predominant clinical feature is localized pain. The pain is often dull and boring, continuous, or intermittent. It characteristically worsens at night, and it is relieved via non-steroidal anti-inflammatory drugs (NSAIDs), which is consistent with the finding in the present case. Various theories have been advanced to explain the precise nature of the pain and its tendency to worsen at night. Some authors believe that prostaglandins, especially prostaglandin E2, play a major role in pain worsening at night. Indeed, the nidus of osteoid osteoma contains high concentration of prostaglandin E2 and prostacyclin, which explains the pain and the good response to aspirin and other NSAIDs. Other authors believe that the rich vascularity brings about innervations of the free nerve endings or direct irritation of the nerve fibers, leading to pain and tenderness , 9.Regarding radiological diagnosis, standard radiography  remains the first-line examination. In the present case, the patient's wrong position did not allow to visualize the image and to establish the right diagnosis. This shows the importance of mastering the technique when performing panoramic radiography. In the present case, the region of the posterior mandibular basilar border coincided exactly with the projection of the hyoid bone on this site. Standard radiography must be complemented with three-dimensional imaging (computed tomography scanner or cone-beam computed tomography [CBCT]), which is the reference imaging in the diagnosis of osteoma osteoid. In dentistry, such cases are underdiagnosed since these small lesions could be missed on panoramic radiograph because of the complex anatomic site of the jaws. Indeed, CT scan or CBCT are useful imaging modalities for the diagnosis of lesions having small size. CT scans are currently the best radiographic examination for the diagnosis of osteoid osteoma. Indeed, they allow to show more details regarding the relationship between the tumor and the adjacent structures compared to conventional radiography. Furthermore, sclerotic changes of the adjacent bone and the periosteal reaction are also well demonstrated. Bone scintigraphy is useful for an early diagnosis and for guiding more precise complementary examinations. Magnetic resonance imaging (MRI), which has the advantage of being non-irradiating, is indicated when the medullary bone is affected. It is also indicated to guide diagnosis when other imaging techniques are not conclusive , 10. In Radiographically, the typical nidus of osteoid osteoma is a round or ovoid radiolucency, less than 1 cm in diameter, having a small or no radiopacity in the center, surrounded by reactive sclerosis of the bone, and sometimes with thick homogenous periosteal reaction . OsteoidIn the present case, the axial and coronal sections of the scanner allowed to detect the radiolucent nidus with very small radio-opacity in the center and the peripheral osteosclerosis. In the present case, osteoid osteoma was located in the cortical bone.Histologically, Jaffe described the nidus of osteoid osteoma as a hard osseous core composed of densely set trabeculae of newly formed bone, which is atypical. Jaffe defined the initial notable changes in this tumor as an increased vascularization and destruction with replacement by new atypical bone following the resorption of the demolished tissue. The stroma consists of osteogenic connective tissues, including multiple blood channels . No cellAccording to the classification of tumors having odontogenic and non-odontogenic origins, osteoid osteoma belongs to the group of non-odontogenic tumors. In fact, non-odontogenic tumors of the jaws are rare, and they are often badly understood, resulting in delayed diagnosis and treatment. Differential diagnosis arises mainly with osteoblastoma, ossifying fibroma, fibrous dysplasia, central giant cell granuloma, osteoma, and chronic osteitis with sequestrum . All of The main differential diagnosis of osteoid osteoma is osteoblastoma. Both of them share many clinical, radiological, and even histological features. Similar to osteoid osteoma, the symptoms in osteoblastoma may be absent or may manifest as pain and tenderness. However, they do not have the characteristic feature of night pain that improves with aspirin and other NSAIDs, which is typical of osteoid osteoma . Unlike In the literature, complete excision is the treatment of choice. Spontaneous pain disappears immediately after the surgery, as reported in the present case . RecentlCorrect diagnosis of osteoid osteoma is based on the elements of clinical semiology together with the imaging findings. A wrong radiological technique or a misinterpreted radio-clinical approach inevitably leads to an incorrect diagnosis and treatment. To confirm diagnosis, the anatomopathological examination is required.


Primary testicular non-Hodgkin’s lymphoma (PTNHL) with contiguous involvement of the spermatic cord is a rare occurrence and presentation of the disease, and it mostly involves elderly men between the sixth and eighth decades of life. PTNHL is a rare form of primary testicular malignancy that accounts for 1% of all non-Hodgkin's lymphoma cases and 5-10%of all testicular malignancies.This case report discusses a 73-year-old man who presented with right-sided inguinoscrotal swelling for six months, which had progressively increased in size. The patient was referred to the surgical department, and the examination revealed a hard-palpable mass with thickening of the cord. The initial imaging included an ultrasound, demonstrating a heteroechoic mass inseparable from the right testis with evidence of mild increased internal vascularity. Due to the high suspicion of malignancy, a right orchidectomy was performed. The patient subsequently developed another swelling after seven months, over the right inguinal region, which had progressively increased in size. MRI of the pelvis and CT of the abdomen and chest revealed a lobulated, intermediate intense lesion in the right inguinoscrotal region.This case report demonstrates the importance of radiological imaging in assessing and detecting the characteristics of concomitant lesions by using various imaging modalities and assessing the extent of spread. In addition, radiological imaging helps in the early diagnosis of the disease and facilitates prompt and early treatment to achieve favorable outcomes for the patient. The radiologist should include a differential diagnosis of PTNHL when imaging for a painless inguinoscrotal mass. Lymphoma can initially present within the testis, and primary testicular non-Hodgkin’s lymphoma (PTNHL) and primary spermatic cord lymphoma (PSCL) are rare variants of gonadal tumors . Both ofIn this report, we aim to use the imaging features to identify, detect, stage, and assess the extent of the disease, and to help differentiate it from other gonadal tumors. The ultrasound plays an important role as the initial and basic modality to visualize the tumor followed by enhanced imaging modalities that aid in the diagnosis and thus benefit the patient. The risk factors include a history of cryptorchidism, recurrent orchitis, and trauma; however, these risk factors are not established entities, and the only risk factor that has a strong association is an HIV infection .A 73-year-old man presented with a six-month history of right-sided inguinoscrotal painless swelling. The patient was referred to the surgical outpatient department. Examination findings revealed a hard palpable mass of 10 x 5 cm with thickening of the cord; the patient was subsequently referred for an ultrasound, which demonstrated a heteroechoic mass of 4.6 x 4.0 x 3.5 cm Figures  that wasAn initial diagnosis of a mass of neoplastic origin was made and initial management involving right-sided low-level orchidectomy was performed. Intraoperatively, surgeons found a hard mass entirely replacing the right testis and epididymis measuring approximately 8 x 5 cm, with a thickened and nodular cord up to the level of the superficial inguinal ring Figures -6.The samples were sent for histopathological studies within the pathology department, which revealed diffuse sheets and discrete medium to large atypical cells with pale eosinophilic to clear cytoplasm, vesicular nuclei, prominent nucleoli, and increased mitosis Figures -9. The tFurther imaging, including CT and MRI, was undertaken to investigate any spread of the disease. Imaging of the following regions was carried out: an MRI of the head and neck Figure  and a CTAfter seven months, the patient returned with swelling over the right inguinal region, which had progressively increased in size. It was examined by the surgeons, which revealed a hard mass of size almost 9 x 6 cm in the right inguinal region; the patient was advised to undergo an MRI of the pelvis along with a CT of the abdomen and chest. The imaging revealed a lobulated, predominantly long TE/TR and short TE/TR sequence intermediate intense lesion measuring 8.5 x 7.0 x 6.0 cm, noted in the right inguinoscrotal region, The lesion was inseparable from the righty cord structures at the root of the scrotum with features of encasement Figures -15.Small nodules of similar intensity were noted within the scrotal sac. Testis was not recognized separately, consistent with surgical history. The overlying subcutaneous fat plane was inflamed. Screening imaging using both MRI and CT Figures -18 of thThe patient then underwent high ligation of the cord structures with mass excision and superficial lymph node resection, and the samples were sent for histopathological correlation, which revealed a monotonous population of cells arranged in sheets and in trabeculae. The cells had eosinophilic to clear cytoplasm with pleomorphic vesicular nuclei with some showing irregular nuclear membranes with one to three prominent nucleoli with high mitotic rate, suggestive of recurrence of diffuse B-cell lymphoma. Furthermore, the patient was advised to undergo high-dose chemotherapy with autologous stem cell transplantation; however, due to its high cost, the patient opted to undergo second-line therapy with chemotherapic agents, which included a combination of ifosfamide + carboplatin + etoposide regimen (ICE regimen) for four cycles with a gap of three weeks between the cycles at the same government-funded higher clinical center.During the following four months, the patient developed a swelling over the superior aspect of the right shoulder. Fine needle aspiration cytology was undertaken from this site, which revealed atypical pleomorphic cells, consistent with an atypical lymphoproliferative disorder, which suggested dissemination of the disease to the medial end of the right clavicle; following this, the patient was lost to follow-up.PTNHL is a rare form of primary testicular malignancy that accounts for 1%  of all nSpermatic cord lymphoma is an unusual variety of lymphoma and a rare form of primary spermatic cord malignancy. It accounts for 1.6% of spermatic cord tumors . Most ofPrimary spermatic cord lymphoma is a very rare variant of non-Hodgkin’s lymphoma. It is a lethal form of lymphoma that causes detrimental effects even in the early stages of the disease progression. Gonadal lymphoma is rare , and theThe patient commonly presents with a painless mass on either side. The mass is seen to be inseparable from the testis and palpated as firm in consistency. Other symptoms include weight loss, loss of appetite, and night sweats, as well as an associated hydrocele in almost half of the cases . SonograIn CT, the lesion generally appears as a heterogenous mass, which is predominantly hypodense and enhances heterogeneously. In post-contrast studies, the lesion mostly replaces the testis and epididymis parenchyma and is usually associated with a hydrocele. CT is further used to visualize para-testicular spaces and staging for which the Arbor classification is used . MRI shoThe treatment usually includes orchidectomy, which is both diagnostic and therapeutic, followed by chemotherapy and radiotherapy. A combined approach can also be undertaken . ProphylFurther differentials can include secondary involvement of testis, following widespread involvement of non-Hodgkin lymphoma, as well as epididymo-orchitis; however, this can be excluded since the patient had no other typical associated symptoms of epididymo-orchitis like pain and fever. Although most of the cases had pain as an associated symptom, a few cases of chronic epididymo-orchitis can present as an infiltrative mass of the scrotum, which is very difficult to differentiate from PTNHL. In this case, orchidectomy is undertaken for diagnosis confirmation, whereas in other differentials such as germ cell tumors, it often invades the retroperitoneal group of lymph nodes. This presentation was absent in our case; in addition, germ cell tumors are associated with elevated serum human chorionic gonadotrophin and alpha-fetoprotein, which is not seen in the case of PTNHL.Testicular cancer is commonly considered to have a good prognosis, with the advent of modern medical applications such as precise surgical excision, in addition to high-quality/detailed imaging modalities and advanced therapies such as chemo/radiotherapy. In our case, there was a significant relapse rate. Thanks to advanced imaging techniques, early detection is possible and the disease can be differentiated from other potential conditions, and the extent of the disease can be assessed so that the outcome can be favorable. Radiologists play an important role in achieving favorable outcomes for the patient. It is thus essential that radiologists are aware of the various differentials for the painless inguinoscrotal mass, and they should consider PTNHL as a differential when assessing an elderly male patient with a unilateral painless swelling.


An 8-month-old, intact male, domestic shorthair cat was referred for a mass on the proximal ventral part of the tail which had been found since the animal was born, and due to the presence of a linear fissure with rows of ectopic teeth, the veterinarian suspected that the mass had recently ruptured. Tail amputation was elected and the entire mass was successfully surgically excised. From the gross examination, this mass had an open cyst-like structure with a prominent area composed of hair, teeth, and bone. Histopathology revealed two components of germinal layers including hair follicles, adnexal tissue, neural tissue, teeth, muscle, fat, bone, and lymphatic vessels. The histopathological diagnosis was consistent to mature teratoma. Although, complete excision could not be definitively confirmed histologically, this kitten is currently well and has not developed any recurrent mass at the surgical site after 2 years of post-operation. Teratomas are germ cell tumors and are rarely reported in domestic animals. The unique feature of this tumor is the presence of multiple embryonic germ layers including ectoderm , mesoderm  and endoderm . Teratomas commonly occur in an ovary or cryptorchid testicle; however, a few cases of extragonadal teratomas have been reported in cats at retrobulbar, head, perineal and coccygeal areas –4. BasedAn 8-month-old, domestic short hair, intact male cat was presented to a private animal hospital with a chief complaint of a slow growing skin mass on the ventral tail between the 1st to 8th coccygeal vertebrae  observedThe mass was submitted to the Veterinary Diagnostic Center, Faculty of Veterinary Science, Mahidol University for histopathologic examination. Upon gross dissection, the mass revealed a large central space with associated clusters of canine, premolar and molar teeth and small bones scattered over haired skin. The associated multilobulated bulks of adipose tissue, comprising the sac wall ,C, was lHistologically the dermis was regionally expanded by a variably cellular, multilobulated proliferation of neoplastic cells that exhibited differentiation toward two primordial germ cell layers including ectoderm and mesoderm. For the ectoderm, there were areas of eosinophilic granular and fibrillar neuropil along with neural parenchyma of respective gray and white matter containing variable numbers of glial cells and neurons , often iTissues were immunostained for pan-cytokeratin , vimentin , glial fibrillary acidic protein , neuron-n , alpha smooth muscle actin  and CD31 . Squamous epithelial cells lining the epidermis, adnexal structures and follicular cyst showed strong cytoplasmic immunolabelling against pan-CK. In regions of neural tissue, several glial cells were immunoreactive for GFAP . Some neTFAP2C and PRDM1, transcription factor genes, in misplaced germ cells could lead to altered epigenetics germline program and tumor formation   . In catsaumanni) , 17, 18.aumanni) , 6.KIT, PRDM1, and TFAP2C), and pluripotent factors (ALPL and SOX2). When compared between immature and mature of sacrococcygeal teratoma, immature group showed a different genetic expression pattern of ribosomes, histones, cytoskeleton and transcription regulators. On the other hand, mature sacrococcygeal teratoma had a higher gene activation of innate and adaptive immune effectors (In humans, extragonadal teratomas were reported in the midline locations including sacrum, presacral space, coccyx, mediastinum, retroperitoneum, and intracranial space . The criffectors . In catsffectors , retrobuffectors  of kitteffectors . Howeverffectors .In the present case, although endodermal elements such as respiratory and alimentary tissues were not observed. However, histologically, the presence of well-differentiated tissue of ectoderm and mesoderm within the neoplasm warrants a diagnosis of mature extragonadal teratoma at the base of the tail of a young cat. Additionally, several immunohistochemical markers including GFAP, neuron-n, pan-CK, vimentin and SMA aid the evaluation of degree of tissue differentiation. Comparing with the previous report of feline coccygeal teratoma, the present case also occurred at a similar age and location, with no evidence of invasion to the caudal vertebrae. In contrast, the previously reported case had all three primordial germ layers with immature tissue components highlighted by Sox-2. In this study, tail amputation should be a curative resection and there was no recurrent mass observed after 2 years of tail amputation. Taking all findings together, mature teratoma was confirmed and benign biological behavior was supposed. Although local recurrences or metastases are unlikely in this case, periodic monitoring of the surgical site remains recommended due to the unclean surgical margin.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.Written informed consent was obtained from the owners for the participation of their animals in this study.SS and TK contributed to conception and design of the case description, wrote original draft, review, and editing. NS, NA, ST, and AR contributed to resources. All authors contributed to manuscript revision, read, and approved the submitted version.This study was partially supported by the Center of Excellence for Companion Animal Cancer, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University.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.


Periapical implantitis (IPL) is an increasingly frequent complication of dental implants. The causes of this condition are not yet entirely clear, although a bacterial component is certainly part of the etiology. In this case series study, two approaches will be described: because of persistent IPL symptoms, a patient had the implant removed and underwent histological analysis after week 6 from implantation. The histomorphometric examination revealed a 35% bone-implant contact area involving the coronal two-thirds of the implant. The apical portion of the fixture on the other hand was affected by an inflammatory process detectable on radiography as a radiolucent area. The presence of a probable root fragment, detectable as an imprecise radiopaque mass in the zone where the implant was later placed, confirms the probable bacterial etiology of this case of IPL. On the other hand, in case number 2, the presence of IPL around the fixture was solved by surgically removing the implant apical third as well as the adjacent tooth apex. It may be concluded from our histological examination that removal of the apical portion of the fixture should be considered an effective treatment for IPL since the remaining implant segment remains optimally osseointegrated and capable of continuing its function as a prosthetic abutment. Careful attention, however, is required at the implantation planning stage to identify in advance any sources of infection in the edentulous area of interest which might compromise the final outcome. Although the predictability of endosseous implants is well supported in studies, the possibility of failure in the long and short term still exists . ImplantThe clinical signs of early failure of an implant are local inflammation of the peri-implant hard and soft tissue, defined above as “peri-implantitis”, and sometimes accompanied by secretion of purulent exudate, bleeding, and probing depth more than 3 mm. Histological findings from the peri-implant area include the presence of an inflammatory cellular infiltrate, epithelial proliferation, bacteria, and ultimately areas of osseous necrosis . RadiogrThe most common type of peri-implantitis generally involves the more coronal part of the implant and only later tends to spread in the apical direction, sometimes leaving the apical portion of the fixture still firmly integrated in the crestal bone .It may happen occasionally that peri-implantitis will develop apically in the same manner as a periapical lesion of a dental structure, i.e., without involvement of the coronal crest bone. This particular condition has been defined as implant periapical lesion (IPL), apical peri-implantitis, retrograde peri-implantitis, or endodontic implant pathology. It should be considered a distinct form relative to the more common form of peri-implantitis, which involves the coronal portion of the fixture ,8.A retrospective study of approximately 3800 implants found an IPL incidence of 0.26%. In another study, Quirynen reported an IPL incidence of 1.6% in the maxilla and 2.7% in the mandible ,10.The best evidence-supported etiology of IPL is diffusion of pathogenic bacteria from infected dental remnants present in the bone around the tip of the implant, or implant-adjacent dental structures with endodontic periapical lesions ,10. DepeThis article describes two cases of IPL, which were treated with two different approaches: a surgical removal of the entire affected fixture and a surgical removal of just the apical third of the implant as well as the adjacent tooth apex. A 45-year-old patient in good general health, non-smoker, with partial edentulism in the right mandible, presented to our service for rehabilitation of the missing structures with implant-supported prostheses.On presentation, the patient was already edentulous in the area of the right mandibular second premolar and the first and second molar for more than 10 years. Before developing an adequate treatment plan, we ordered a pantomograph , after wThe CT scan demonstrated the presence of a small area of radiopacity of the bony structure at teeth 46–47, the nature of which could not be defined . The patSeveral hours after the intervention and on subsequent days, the patient spontaneously reported continuous pain of a pulsating type, similar to pulpits pain, close to the right mandibular molar area. The authors made the diagnosis of IPL after intraoral radiographic examination. The IPL was relieved only through administration of an analgesic , but no neurosensory changes were reported for the right mandible.The IPL symptoms lasted for more than a month from the date of the intervention, during which intraoral radiographs were taken to detect possible abnormalities in loading of the peri-implant hard tissue. The implant at tooth 47 did not present any bleeding or probing depth more than 3 mm, but an intraoral radiograph showed an area of radiolucency close to the apical segment of the fixture B. BecausAfter approximately three months from the intervention, in which no complications were observed, we proceeded to mount prostheses on the implants at teeth 45 and 46, which consisted in a two-unit fixed partial denture supported on 2 implants at #45 and #46 D.The drilled implant was preserved in buffered formalin 10%, dehydrated in a progressive series of washings with alcohol, and embedded in glycol methacrylic resin in preparation for histological analysis . After polymerization, the implant was sectioned along its longitudinal axis with a high-speed diamond disk . Sections of approximately 46 µm thickness were obtained and then stained with basic fuchsin and toluidine blue. A second staining procedure was performed with von Kossa and basic fuchsin to evaluate the level of bone mineralization.The histological analysis shows adequate osseointegration in the coronal aspect, with a BIC of approximately 35%, while the apical portion of the implant is totally free of bone. .In September 2020, a 52-year-old patient came to our attention with pain and swelling in the upper right premolar area. The fixture showed no clinical signs of peri-implantitis and no mobility but the whole area was sensitive upon percussion. Upon radiographic examination, a radiolucent area involving the implant apical third as well as the root apex of tooth number 5 was observed A. The roAntibiotic therapy was administered: 1 g amoxicillin/clavulanic acid  every 12 h for 6 days.A para-marginal incision was performed and a full thickness flap raised from tooth number 6 up to tooth number 3 with two vertical relieving incisions B. AccessThe retropreparation of tooth 5 was done with surgical retrotip  and it was filled with Biodentine .The flap was sutured tension-free and the patient was dismissed. After the healing period, the patient noted improvement of the symptoms. One year later, a periapical radiography was taken showing the healing of the periapical radiolucency, the fixture showed no signs and symptoms of peri-implantitis, and tooth number 15 showed no mobility and no symptoms. Probing depth was 2 mm around the tooth and 3 mm around the implant D.The histological analysis of the surrounding tissue revealed the presence of a rich inflammatory tissue.Among implant failures, a significant role seems to be played by apical peri-implantitis (IPL). Different researchers have described cases of IPL—as retrospective studies or case reports—with indications for treatment of this disease and suggestions for possible causes ,27,28,29However, the best evidence-supported etiology of IPL suggested by the different researchers is bacterial in nature ,12,19,22From a statistical perspective, the region most affected by IPL is that of the maxillary premolars . This maIPL has been attributed in a histological study to the amide present on the latex of the gloves. In fact, the presence of amide from gloves has been detected inside neutrophilic granulocytes. However, this may not be the primary cause of IPL in the first case report, since the clinical symptomatology was manifested approximately one month after implant insertion and the adjacent dental structure presented an endodontic apical lesion .Confirmation of the bacterial origin of apical IPL is supported by the finding of types of bacteria in the apical portion of the implant that are very similar to those in endodontic infections, such as Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia, while contrariwise, bacteria typical of periodontal lesions are found in classic peri-implantitis ,36,37,38Our study is one of the few available in the literature that reports an implant affected by apical IPL. The histological analysis revealed complete osteointegration of the coronal two-third of the fixture, whereas the apical portion remained free of contact to bone. This could be due to necrotic tooth remnants found upon CT scan examination. The osteotomy use of surgical burs or the fixture placement itself may have reactivated a latent infection around these tooth fragments, causing an inflammatory reaction in the apical portion of the implant. Our failure in the histological examination to find inflammatory tissue may be due to detachment or to its seclusion within the mandibular bone during drilling of the implant ,9.Other research has also reported the presence of root fragments—not detected during the implantation—which induced inflammatory apical reactions to the fixture .Radiopaque zones in edentulous crests are very frequent in areas where a dental extraction has previously been performed. These may be due to focal osteosclerosis, a non-expansible radiopaque alteration of trabecular bone of unknown origin, asymptomatic, with various shapes and sizes, affecting both the maxilla and the mandible, with higher prevalence in the mandibular molar and premolar region. Its radiopacity may resemble other pathologies of the jaws, such as condensing osteitis, root segments, hypercementosis, cementoblastoma, impacted teeth, focal cemento-osseous dysplasia, and odontomas ,40,41.Focal osteosclerosis can be present in proximity to the retained root tips or in the edentulous crest region . In our Another possible approach that would explain the patient’s painful symptomatology could be injury to the vascular-neural bundle of the alveolar canal occurring during preparation of the implant site. This may be seen also on radiography as an area of radiolucency involving the apex of the implant in close contact with the underlying alveolar canal. However, despite the fact that trunk anesthesia was not performed—to maintain neural sensitivity during the intervention—the patient did not experience any pain during placement of the implant or post-operative paresthesia. Treatment of local IPL consists in the removal of the implant (case report n.1) or removal of its apical portion (case report n.2), with consequent elimination of the inflammatory tissue . RemovalEarly surgical treatment is essential in order to limit progression of the lesion to the osseointegrated part of the fixture. Our histological study shows that this surgical therapy may be helpful in the treatment of IPL since the coronal two-thirds portion of the implant is fully osseointegrated. According to the present literature, some dental remnants may be intentionally left in post-extraction sites without causing infectious complications like the ones experienced by the authors in the first case report. This confirms that infections proceeding from neighboring teeth may cause IPL in fixtures’ periapical tissue. As far as investigated by the authors, only one failure for infectious reasons has been described with the socket shield technique because the apex was left during the surgical procedure. Indeed, the tooth apex and endodontium need to be accurately removed when performing this technique in order to achieve clinical success; only a buccal sliver is meant to be left in situ ,44.Because of the ever-increasing number of people undergoing implant-based treatment in recent years, there has been an increased incidence of apical IPL. The presence of infected root remnants or endodontic periapical lesions seems to be the major cause of this type of implant failure. Treatment of apical IPL should be directed toward elimination of the bacterial noxae and limitation of progression of the lesion to the osseointegrated part of the implant. Removal of the apical portion of the implant appears to be a valid therapeutic option, since the remaining part of the fixture appears from our histological examination to be optimally osseointegrated and not affected by the inflammatory process. Good initial treatment planning seems fundamentally important. It should be targeted toward the identification of local etiological factors present either in the edentulous crest or the adjacent dental structures, and their preventive elimination before insertion of the fixture so as not to compromise implant predictability.


Point-of-care ultrasound (POCUS) is a useful tool for the evaluation of soft tissue masses. We present the case of a patient with a mass on his forehead initially thought to be a slowly resolving hematoma. POCUS examination of the mass revealed a vascular structure more consistent with a post-traumatic arteriovenous malformation (AVM). This case illustrates how POCUS can be utilized to rapidly assess soft tissue masses and even identify unexpected vascularity.  A 59-year-old gentleman with end stage renal disease, coronary artery disease, type 2 diabetes, and hypertension was admitted to the hospital for dyspnea due to mild volume overload. On physical exam, he was noted to have a 3 x 3 cm soft tissue mass on the right forehead with superficial ulceration . His medication list did not contain any anti-platelet agents or anticoagulation. The patient described a hematoma since a mechanical fall while walking on the street 6 weeks prior with impact to his forehead. He had developed swelling immediately after the fall but did not lose consciousness. He presented to the emergency department (ED) at that time where CT head was performed showing a 3 cm prominent right prefrontal soft tissue hematoma. A needle aspiration was performed with reportedly over half of the fluid in the hematoma drained. He was discharged from the ED. Given increased swelling and pain at the site of the hematoma, he returned to the ED 1 week later where the soft tissue swelling was noted to be 4 cm. Given persistent pain, a repeat needle aspiration was performed and 7 ml of blood was removed. Incision and drainage was also performed with clotted blood removed and he was discharged. Fluid specimens were not sent for laboratory analysis at either visit. Since the second visit to the ED, the patient reported that the “hematoma” had recurred status-post aspiration and drainage but was smaller than it was initially and remained painful. Plastic surgery was consulted who noted palpable thrill at lateral aspect of the mass. On POCUS examination, the forehead mass was found to have pulsatile internal flow concerning for a vascularized structure such as an arteriovenous malformation (AVM) . CTA was performed which revealed a 7 mm round pool of contrast at the lesion, supplied by an artery with a questionable draining vein, consistent with an AVM or less likely pseudoaneurysm . Given ongoing pain at the site of the soft tissue mass, the patient was planned for outpatient resection of the vascularized soft tissue mass with interventional radiology support. A superficial soft tissue mass has a broad differential diagnosis which includes lipoma and other tumors, cyst, hematoma, and atypical abscess. Given the inciting trauma and known antecedent hematoma, a slowly resorbing or persistent hematoma was considered possible in this case, but the duration of the mass for >4 weeks would have been very unusual. Lipomas are subcutaneous collections of adipose tissue commonly occurring in the head and neck region. They have been found to occur after trauma but are usually slow growing  POCUS can be helpful in the initial evaluation of a soft tissue mass as it can be used to distinguish some of the characteristic features of this broad differential diagnosis. For lipomas, one would expect to see a lack of blood flow on color Doppler with minimal or no growth on serial measurements using US AV Malformations (AVM) are fistulas between arteries and veins with an incomplete or absent capillary bed in between A vascular imaging modality is necessary to diagnose an AVM and assist in treatment decision making. Formal vascular ultrasound is usually the first imaging modality used due to its ability to be performed at the bedside, low cost, and no radiation or contrast exposure. Ultrasound is limited in its ability to determine depth of invasion into surrounding structures. MRI or CT-angiogram provides better spatial context along with hemodynamic information. The gold standard in diagnosis is a catheter based digital-subtraction angiogram Once a soft tissue mass is diagnosed as an AVM, early intervention through a multidisciplinary approach is best. AVM can be managed conservatively if it is asymptomatic with no distal ischemia or compression. Surgical treatment options include embolization, coiling, resection and transcutaneous scleropathy.POCUS is an essential tool to rapidly evaluate a soft tissue mass. As in the case presented, significant vascularity or arterial flow in a soft tissue mass should raise immediate concern for an AVM or pseudoaneurysm. The patient provided written consent for presentation of his case. None. Video S1


Fibrodysplasia ossificans progressiva (FOP) is a rare disease with less than a thousand confirmed cases. It is a severely disabling genetic condition that affects soft tissues and is characterized by progressive extraskeletal heterotopic ossification and great toe deformities.The mode of FOP inheritance is autosomal dominant with no association to race, gender, or geographic distribution. While laboratory results and imaging studies support the identification of FOP, the diagnosis of this rare condition is mainly clinical. Recently, FOP has been linked to a mutation of the ACVR1/ALK2 gene that induces osteoblast activation. We are reporting four cases of fibrodysplasia ossificans progressiva over a period of two years (2014-2016). Three out of four cases were treated conservatively. The first case was treated by excision of a bony bar, and the patient developed progressive bony formation and restriction of movement afterwards.Almost always, FOP needs to be treated conservatively with non-steroidal anti-inflammatory drugs (NSAIDs) and gentle physiotherapy. Aside from anesthetic complications, surgical interventions provoke more bone formation, hence the recurrent joint restriction. Therefore, surgery should only be reserved for severely disabling deformities. Fibrodysplasia ossificans progressiva (FOP) is a rare and severely disabling genetic condition that affects soft tissues. There are fewer than a thousand cases of FOP, with an estimated number of 3000 to 4000 affected patients ,2. FOP hFOP is caused by a mutation of a bone morphogenetic protein (BMP) type I receptor gene named ACVR1/ALK2 ,5. FolloPathognomonic features of FOP include congenital malformations of the great toes and progressive extraskeletal heterotopic ossification that forms normal bone in specific areas of the body, therefore restricting movement -5. ChildThe rate of progression of FOP widely varies with the heterotopic ossification found to first affect the neck, shoulder, upper back, and chest. FOP tends to progress in a centrifugal pattern from the axial skeleton to the extremities, with the lower extremity affected last. Of note, the diaphragm, cardiac and smooth muscles, tongue, and extra-ocular muscles are not affected by FOP .Patients with FOP will mostly be wheel-chair bound by the third decade of life, and they usually have an average lifespan of 30-40 years ,9. MoreoThe diagnosis of FOP is usually clinical. Laboratory investigations such as alkaline phosphatase support diagnosis. While imaging studies such as X-rays and computed tomography (CT) scans identify mature heterotopic ossification, other imaging modalities such as ultrasound, MRI, and most recently, positron emission tomography (PET) scans detect early ossification. Identification of the ACVR1/ALK2 gene mutation confirms the diagnosis .Supportive therapy remains the mainstay of treatment for FOP as there is no definitive management yet. This includes avoidance of triggering factors such as trivial trauma, gentle physiotherapy, and occupational therapy. A short course of steroid injections was found to be helpful during flare-ups; however, injections in general, including some childhood vaccines, have to be avoided if possible to prevent further inflammatory derives .Currently, there are few ongoing in vitro trials at the molecular level to inhibit the heterotopic ossification of FOP. Surgical options to excise these heterotopic ossifications have to be avoided as surgery represents a triggering factor ,13.Report of four casesFour cases were diagnosed with fibrodysplasia ossificans progressiva within a period of two years (2014-2016) at Omdurman Military Hospital, Khartoum, Sudan.Case 1A 10-year-old male was referred to our orthopaedic department for limited shoulder range of movement and truncal swelling noticed over a period of one year. He was the outcome of a normal delivery, passed through normal milestones, and completed his vaccinations. The patient and his parents denied a history of trauma or recent illness. His symptoms were progressive over one year, but there were no associated red flags or constitutional symptoms. There was no family history of a similar condition. On examination, the child was of average height and weight for his age and had no dysmorphic features. Back examination showed multiple non-tender solid lobules over the upper trunk region. These swellings were firmly attached to underlying structures but not to skin. Both the shoulder's active and passive ranges of the movement were limited to 15 to 45 degrees of abduction; stiff forward and extension movement. He had bilaterally deformed and short big toes Figures -1C. All His parents were very keen on improving his shoulder abduction through surgery. Therefore, after explaining the benefits and risks of surgery , we got written informed consent from the parents. The patient had excision of a very superficial bilateral bony bar extending from the chest wall to both shoulders, which was limiting his shoulder abduction and adduction. He recovered well from surgery and could achieve 120 degrees of abduction. Unfortunately, he ended up with more restrictions on his movement just four months following surgical excision Figure .Case 2A five-year-old girl was referred by her paediatrician for increased stiffness of the trunk, shoulder and elbows six weeks following bronchiolitis. Her elbow active and passive range of motion was from 90 to 110 of flexion Figure -2B. BackCase 3An 11-year-old boy was brought in by his parents for restricted shoulder movement and a stiff neck. He showed the same bony lumps all over the back, neck, and front part of the shoulder Figure . After rCase 4A seven-month-old female was referred by her paediatrician for delayed motor milestones and neck stiffness. She was the outcome of normal delivery with no dysmorphic features. Physical examination revealed the involvement of the trunk: the cervical region was most affected, as were both shoulders and the bilateral big toe deformity Figure -4B. The Fibrodysplasia ossificans progressiva is a rare and severely disabling genetic condition that affects soft tissues. It is characterized by progressive extraskeletal heterotopic ossification and great toe deformities ,2. DiagnCurrently, there is no satisfactory treatment for FOP; however, physicians have tried a short course of steroids within the first days of the flare-ups to halt the inflammatory process ,15. MoreOf the four cases reported here, three were treated conservatively with non-steroidal anti-inflammatory drugs (NSAIDs) and physiotherapy. In the first reported case, the parents were aware of complications after surgery; however, they were insistently pressing towards the excision of the transverse bony bars bilaterally. Therefore, the orthopaedic team at Omdurman Military Hospital decided to proceed. The MDT meeting, including anaesthetics, orthopaedics, nurses, and physiotherapists, was held first to address the risks of intra-operative and post-operative complications that could follow intravenous/intramuscular injections, intubation, and jaw handling, as well as postoperative physiotherapy.Unfortunately, the boy had a recurrence of shoulder stiffness within four months. Jayasundara et al.  showed aThe orthopaedic team knew that they were going against most of the literature; however, there were few articles with short-term follow-up reporting successful excision. Ozkan et al.  and MoorDi Rocco et al. advised against surgical options because surgery represents a triggering factor, and they recommended a short course of oral steroids before and after surgery as a preventive measure if intervention is unavoidable . MoreoveFibrodysplasia ossificans progressiva is a rare genetic disabling condition that requires a high index of suspicion when examining a child with big toe deformity and heterotopic ossification. Laboratory results, including genetics and imaging studies, support the diagnosis of FOP, and treatment is almost always conservative.Aside from the anaesthetic complications, surgical excision of heterotopic bone in FOP patients produces more bone formation, hence the recurrent restriction of joint movement. Therefore, based on our experience, we recommend that surgery should only be reserved for severely disabling deformities.