Ectopic meningioma occurring in the region of parapharyngeal space is rare inclinical practice and brings great challenge in its diagnosis. This reportdetails such a case in a 14-year-old girl with neurofibromatosis Type 2, whichis a highly infrequent association. The clinical manifestations, imagingfindings, and pathological manifestations are described, and the relevantliterature is reviewed to highlight characteristic imaging findings of ectopicmeningiomas. Neurofibromatosis Type 2 (NF2) is a genetic neoplastic disorder thatpresents with multiple meningiomas and bilateral vestibular schwannomas,8 and most meningiomas associated with NF2 arise intracranially. Herein, wereport the clinical signs, imaging findings, and pathological manifestations of arare case of meningioma occupying the parapharyngeal space in a patient withNF2.Meningiomas are among the most common tumours of the central nervous system,accounting for nearly 20% of primary intracranial tumours.Our patient, a 14-year-old girl, presented with a 4 month history of a painless massin the right retroauricular area; it was first found in June 2015. Clinicalexamination revealed a mass approximately 4 × 3 cm in size . The neuT1 weighted imaging (T1WI) and slightly hyperintense on T2 weighted imaging (T2WI) and accompanied by multiple focal hypointensities that might havesuggested calcification. Marked but heterogeneous enhancement was observed after theadministration of gadolinium. Diffusion-weighted imaging revealed diffusionrestriction; the average apparent diffusion coefficient  value was 699.7 ×10−6 mm2 s–1  staining revealed that there was a heavy deposit of collagen fibersbetween the tumour cells; multiple psammoma bodies were also seen. The tumour itselfconsisted mainly of bundles of elongated spindle-shaped cells with small ovalnuclei. The typical whorl structure of meningioma was observed in some areas.Immunohistochemical staining showed that the tumour cells were positive forprogesterone receptor, epithelial membrane antigen, and vimentin and negative forS-100 protein, CK, CD68, and P53. The Ki-67 labelling index was less than1%. In view1 Four hypotheses regarding the development of ectopic meningiomas have beenproposed; that they arise due to (1) metastasis from an intracranial meningioma, (2)direct extension from an intracranial lesion, (3) growth from embryonic nests ofarachnoid cells, and (4) the development of arachnoid cells within cranial nerve sheaths.10 According to these hypotheses, our case may have arisen from the cranialnerves with extracranial parapharyngeal extension. It has also been suggested thatprimary ectopic meningiomas of the head and neck are related to neurofibromatosis,particularly NF2. NF2 is caused by a mutation in a tumour suppressor gene onchromosome 22q12 and is characterized by vestibular schwannomas and meningiomas.11 Extracranial meningiomas are extremely rare, with an overall incidence of 1–2%.12 The dural tail sign is, however, not detected outside of the brain, in ourcase it could not aid in the diagnosis. We did find multiple focal hypointensitieson T1WI and T2WI, which might have suggested calcification. MRI is an essentialdiagnostic tool for the identification of parapharyngeal masses and can reflect theextent of the tumour. These imaging modalities are also extremely useful inpre-operative surgical planning.The diagnosis of ectopic meningioma is difficult to make on the basis of imagingalone. On MRI, meningiomas usually have homogenous contrast enhancement and signalintensity similar to that of other brain lesions. The diagnosis of ectopicmeningioma in the parapharyngeal space is particularly challenging, since the morecommon tumours occurring in this anatomical space include neurogenic tumours andparagangliomas. Often, the dural tail component, intracranial extension, anddemonstration of calcification should prompt the clinician to consider thepossibility of meningioma.5 The finding of multiple psammoma bodies and typical whorl formations furtherconfirmed the diagnosis of meningioma.5 Immunohistochemistry is an essential tool for confirming the diagnosis ofextracranial meningioma. The tumour cells in our report showed positive staining forepithelial membrane antigen and vimentin, which further supported the diagnosis.A definitive diagnosis depends on histopathological and immunohistochemical findings.It is axiomatic that the histopathological and immunohistochemical findings forectopic meningioma are similar to those for other intracranial lesions. In thiscase, H-E staining revealed that the tumour consisted of collagen fibres andelongated spindle cells, which are common features of meningioma.8 However, decisions regarding therapy in cases such as ours must be made on anindividual basis. Previous studies have reported that meningioma is a marker ofdisease severity in NF2, being associated with a 2.5- fold greater risk of mortalityas compared with NF2 patients without meningiomas.13 The patient in our case was not offered treatment because, after 2 years offollow-up, she had no new symptoms and the mass was still of almost the same size.In a word, the prognosis of ectopic meningioma appears to be good, with an overallmedian survival of 28 years. However, in any individual case, an estimate ofsurvival is decided by the tumour’s histological type, anatomic site, andgrade as well as the patient’s age.1Although the current standard of care for meningiomas is surgery, NF2-associatedmeningiomas and all developing masses can be resected by stereotactic radiosurgery,a non-invasive form treatment.The possibility of an ectopic meningioma should be considered if a lesion isfound in the parapharyngeal space of a patient with NF2.The imaging and histopathological findings of an ectopic meningioma in theparapharyngeal space are indistinguishable from the findings of otherintracranial lesions.MRI plays an important role in the diagnosis. This imaging modality is alsoextremely useful in surgical planning and subsequent follow-up.


Aortocaval fistula is an abnormal vascular communication between an aortic aneurysm and the inferior vena cava. The condition is very rare and life threatening with high mortality. This article reports a case of aortocaval fistula in a 76-year-old male diagnosed using computed tomography. Computed tomography, being a non-invasive investigation, ensures early diagnosis and can help in prompt surgical or interventional radiological management which can be life-saving. While evaluating an AAA on computed tomography (CT), certain imaging findings can help in diagnosing ACF.Aortocaval fistula (ACF) is a rare complication of abdominal aortic aneurysm (AAA) and is associated with a high mortality rate. It is seen in about 4% of surgeries for ruptured aneurysms.A 76-year-old male patient presented with severe abdominal pain associated with breathing difficulty. On examination, the patient was hypotensive with tachycardia and a pulsatile abdominal mass. Emergency ultrasonography (US) revealed an infrarenal aortic aneurysm with peripheral thrombus.For further evaluation of the extent of aneurysm, emergency CT angiography was performed using a dual slice helical CT scan . A total of 100 mL of non-ionic contrast medium iopamidol , was injected in the right antecubital vein at a flow rate of 4 mL/s. Image acquisition was started after a delay of 22 s. The CT parameters were 120 kV, 120 mA, 2 mm slice thickness and 1.5 pitch. The area of coverage extended from the sternal angle to the inguinal region.The scan showed a large infrarenal fusiform AAA with a partially thrombosed periphery. Active extra luminal extravasation of contrast was seen from the right lateral wall, into the peritoneal cavity  and 3a.There was a fistulous communication on the right posterolateral wall of aorta with the inferior vena cava (IVC), with a flap displaced into the IVC about 4.5 cm distal to the origin of the renal arteries . The lowIn view of these findings, a diagnosis of a ruptured AAA with an ACF was made. The patient was planned for emergency surgery. However, he suffered a cardiac arrest before being shifted to the operating room and could not be revived.1 Men in the sixth to seventh decade are commonly affected. According to a recently proposed mechanism, development of ACF involves pressure necrosis of the aortic wall from the aortic aneurysm. This leads to severe periaortic inflammation causing adherence of an aneurysm to the IVC, subsequently eroding into it. Various risk factors include atherosclerosis, mycotic aneurysm, syphilis, polyarteritis nodosa and connective tissue disorders like Marfan syndrome and Ehlers–Danlos syndrome.2Abdominal aortic aneurysms mostly rupture into the retro-peritoneum or peritoneal cavity. Aortocaval fistula is a rare complication of an aortic aneurysm which can occur spontaneously in 1% of patients or along with rupture in 4% of patients.3 Other symptoms include shortness of breath, cold extremities, cyanosis, haematuria and pulmonary oedema. Long-standing fistulas often present with features of high output cardiac failure.4The clinical presentation depends upon the acuteness of the condition and the presence of other associated findings, like rupture and dissection. A palpable pulsatile mass with a continuous bruit in a haemodynamically stable patient suggests an unruptured AAA, whereas a ruptured aneurysm presents with severe abdominal pain, hypotension and shock.5Preoperative diagnosis is important in planning the operative management and preventing further complications. According to one study, mortality rate in open surgical repair of ACF was around 30%, mainly from excessive blood loss, but it was significantly lower if a preoperative diagnosis was available.6 Aortography is confirmative in diagnosing the ACF.Ultrasound examination can be the initial imaging modality to diagnose AAA but has a very limited role in diagnosing ACF. Multidetector CT angiography is the preferred investigation. Simultaneous presence of contrast in the aorta and IVC during the arterial phase is the most important diagnostic sign and this was demonstrated in our patient. Quite often, the aneurysm compresses the IVC, thereby making it difficult to evaluate this sign. The screening of the iliac veins and renal veins is very significant in such situations as they may be opacified synchronously and with similar attenuation to the aorta. The reflux of contrast from the right atrium should not be mistaken as ACF, as it is of less attenuation. The presence of a fistulous communication between the aorta and IVC is not seen in all cases but was demonstrated in our patient. Additional signs which help in diagnosing an ACF are the loss of the fat plane between the aorta and IVC, poor perfusion of kidneys and presence of aneurysmal rupture.5Successful treatment of ACFs depends upon early preoperative diagnosis, proper operative planning, haemodynamic stabilisation and prevention of pulmonary embolism. Open surgical repair or endovascular repair forms the mainstay of treatment. Endovascular repair has the advantage of less blood loss as compared to the open repair with equal success.In conclusion, ACF is a rare complication of AAA, associated with a high mortality rate. Timely diagnosis is possible by pursuing certain findings at CT imaging which can aid in proper surgical or endovascular planning.


Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography or magnetic resonance imaging of the brain. Calvarial lesions can be benign or malignant. Although the majority of skull lesions are benign, it is important to be familiar with their imaging characteristics and to recognise those with malignant features where more aggressive management is needed. Clinical information such as the age of the patient, as well as the patient’s history is fundamental in making the correct diagnosis. In this article, we will review the imaging features of both common and uncommon calvarial lesions, as well as mimics of these lesions found in clinical practice.• Skull lesions are usually discovered incidentally; they can be benign or malignant.• Metastases are the most frequent cause of skull lesions.• Metastatic lesions are most commonly due to breast cancer in adults and neuroblastoma in children.• Multiple myeloma presents as the classic “punched out” lytic lesions on radiographs.• Eosinophilic granuloma is an osteolytic lesion with bevelled edges. Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography (CT) or magnetic resonance imaging (MRI) of the brain or as part of workup of local clinical symptoms or staging of other diseases –6. OccasThe skull vault is formed by the frontal, parietal, temporal and occipital bones and parts of the zygoma and sphenoid bone. It is composed of two cortical tables; the inner and outer tables, and the diploe or marrow space between them Fig.  1, 4]. , 4. 1, 4Recognition of benign and malignant imaging features is important for the radiological diagnosis –6. In geCalvarial lesions are radiologically evaluated with CT and MRI. CT is the most accurate method for evaluating bone destruction of the inner and outer tables, the lytic or sclerotic nature of the lesion and for the evaluation of mineralised tumour matrix –3, 6. MRThe differential diagnosis of calvarial lesions is important to decide whether biopsy, surgical intervention or conservative treatment is required for further management , 2, 6. IFibrous dysplasia represents 2.5% of all osseous and 7% of all benign osseous neoplasms , 9. It iCT demonstrates an intradiploic, expansile lesion with the characteristic “ground-glass matrix” in all or part of the lesion Fig.  1–9]. T–9. T1–9]Treatment is based on bisphosphonates. Surgical decompression is performed when there is severe mass effect .Osteoma is the most frequent benign tumour in adults and is most commonly seen in men between the fourth and fifth decades of life , 2. It iOn CT, an osteoma is a juxta-cortical, well-defined, sclerotic, homogenous lesion , 2, 4–6.Osteomas do not require treatment unless they cause mass effect and disturb surrounding structures , 2.Langerhans cell histiocytosis (LCH), formerly known as “histiocytosis X” is due to an idiopathic proliferation of Langerhans cells in various tissues  causing focal or systemic disease , 10, 11.On radiographs, there may be one or multiple well-defined punched-out osteolytic lesions , 2, 4, 6On CT, the early appearance of LCH is an osteolytic lesion with bevelled edges due to unequal involvement of the inner and outer tables Fig.  1, 2, 44–6, 10. MRI may aid in the depiction of bone marrow or soft tissue involvement, but the signal intensity of these lesions is non-specific; however, extensive bone marrow oedema is typically present , 12. MosTreatment varies depending on the severity and bony extent. Single lesions can be treated with surveillance or systemic corticosteroids. In the more aggressive forms of disease, surgical excision, radiotherapy and chemotherapy are treatment options .The International Society for the Study of Vascular Anomalies (ISSVA) classification system divides vascular anomalies into two primary biological categories: vascular neoplasms and vascular malformations –15. VascOn plain radiographs, this vascular tumour presents as an osteolytic lesion with the characteristic “sunburst” or “honeycomb” trabecular pattern, which is due to thickened trabeculae adjacent to the angiomatous channels , 16–18. Treatment of these lesions is mainly surgical; embolisation may be performed before surgical intervention to reduce blood loss .Meningiomas are the most common extra-axial dural based tumours in middle-aged and elderly patients , 6, 19. The meningiomas arising outside the dural compartment have been called ectopic, extradural or intraosseous meningiomas. Lang et al.  has propIntraosseous meningioma is a rare subtype of meningioma that account for <2% of all meningiomas –22. The Osteoblastic or mixed osteoblastic-osteolyic meningiomas compose most of intraosseous meningiomas, with the purely lytic form being the least common , 4, 19. On CT, an intraosseous meningioma typically appears as a sclerotic lesion with associated hyperostosis of the bone, and irregular and spiculated borders Fig.  2, 4]. , 4. 2, 4In a symptomatic primary intraosseous meningioma, total tumour removal with a wide surgical resection followed by cranial reconstruction is the treatment of choice. If only subtotal resection is possible due to involvement of critical structures within the orbit, paranasal sinuses, or skull base, the residual tumour should be followed radiologically. Adjuvant radiation therapy is recommended if the residual tumour is symptomatic or if there is evidence of disease progression , 19.Paget disease  is a chronic skeletal disorder characterised by abnormal and excessive bone remodelling. Paget disease is estimated to affect approximately 3–4% of individuals older than 40 years , 23–26. Skull involvement in Paget disease can lead to increase in head size, hearing loss and entrapment of the cranial nerves in their respective foramina. When the skull base is involved, there is platybasia and basilar invagination in which the tip of the odontoid projects more than 5 mm above the Chamberlain line between the hard palate and basiocciput , 24.Early in the disease, osteolytic activity predominates. In this phase, advancing osteolysis presents as large areas of radiolucency in the frontal and occipital bones, known as “osteoporosis circumscripta”. The mixed phase is notable for four cardinal features, which comprise advanced osteolysis, coarsening and thickening of bone trabecula, cortical thickening and osseous widening. In this phase, there is homogeneous enlargement of the skull vault, thickening of the tables and trabecula. The fluffy cotton-wool appearance of the skull is characteristic in this phase with diploic dense lesions in previously sclerotic areas Fig. . DiploicAs suspected, MRI features vary depending on the stage of the disease. Initially, during bone resorption, high signal intensity can be seen on T2-weighted images, as well as strong enhancement. In this stage, on T1-weighted MR images, the marrow has decreased signal intensity, generally similar to that of muscle; however, it typically contains small to extensive foci of intermixed, normal and maintained yellow marrow. This feature is important because it excludes malignant transformation. In the mixed phase, the yellow marrow signal is maintained in all pulse sequences. In the late blastic inactive phase, the marrow space has low signal intensity on both T1- and T2-weighted images representing sclerosis , 23, 24.Sarcomatous degeneration of Paget has been described with varying frequency depending on the extent of disease. In patients with widespread skeletal involvement, sarcomatous degeneration may occur in 5–10% of cases, whereas in patients with less skeletal involvement, neoplasm can occur in less than 1% of cases , 27.Treatment relies mainly on bisphosphonates .Sarcoidosis is an inflammatory disorder of unknown cause characterised by the presence of non-caseating granulomas in tissues. Sarcoidosis involves multiple organs, most commonly the lungs, skin and eyes but may be seen in any organ system, including the musculoskeletal system . SkeletaThe lesions are osteolytic with well-demarcated margins and usually multiple. In contrast to metastasis, the calvarial tables are intact. They can also manifest as expansile lesions on CT imaging. MR can be used to assess bone marrow infiltration and associated periosseous soft tissue Fig. . They haPartial or complete resolution of the sarcoid lesions can occur spontaneously . TreatmeOssifying fibroma is a benign fibro-osseous tumour made of highly cellular fibro-osseous connective tissue. It is more often seen in children and young adults and can affect the calvaria in approximately 12% of cases. It is a benign slow-growing tumour, but a subset of these tumours tends to be infiltrative and locally aggressive , 34. ThrOn radiographs, ossifying fibroma appears as a monostotic, round or ovoid, well-demarcated expansile lesion. It may be predominantly cystic or sclerotic depending on the amount of non-calcified versus that of the mineralised regions. On CT, ossifying fibroma is a mass composed of enhancing soft tissue with varying amounts of internal punctate calcifications. Areas of low attenuation caused by cystic changes may be present, and can have internal haemorrhage Fig.  33–35].–35.33–35On MRI, the solid component is usually isointense to muscle on T1-weighted images and isointense to hypointense to muscle on T2-weighted images. Post-contrast images show diffuse and heterogeneous enhancement of the solid component and thin peripheral enhancement of the cystic areas –35. DiffBecause of its locally aggressive nature and high recurrence rate, early detection and complete surgical removal are essential .Epidermoid and dermoid cysts are benign slow-growing lesions that may be congenital or acquired from post-surgical or post-traumatic implantation of epidermal or dermal inclusions within the diploe. Clinically, they manifest as non-tender, slowly expanding masses enlarging over years or decades , 2, 4–6.Epidermoid cysts are lined with squamous epithelium and contain remnants of cholesterol and keratin. Intradiploic epidermoid cysts can occur in any part of the skull, but most commonly occur laterally in the parietal and frontal bones. They are usually discovered in patients between 20 and 50 years of age , 2, 6.On CT, epidermoid cysts appear as well-demarcated intradiploic osteolytic lesions with smooth sclerotic margins. These lesions often cause remodelling and expansion of the inner and outer tables. Rarely, they may have increased attenuation on CT, possibly due to haemorrhage, formation of calcium soaps or high protein content (white epidermoids) , 4–6, 36On MRI, epidermoids have fluid-signal intensity on T1- and T2-weighted images and have characteristic restricted diffusion on diffusion-weighted imaging (DWI). They do not enhance after contrast administration Fig.  1, 2, 44–6, 36.FDermoid cysts are lined by thick squamous epithelium and contain epidermal appendages such as sebaceous glands, sweat glands and hair follicles. They usually present in the first 3 decades of life. These lesions typically involve the midline of the skull near the anterior fontanelle, but may also occur along the posterior and middle cranial fossae , 2, 4–6.On CT, dermoids appear as expansile, osteolytic midline lesions with a soft-tissue component extending into the adjacent soft tissues and intracranially. They have attenuation of lipid material because of their sebaceous secretions. Intralesional calcifications can be present.On MRI, they have a heterogeneous appearance with fatty signal intensity on T1-weighted images, variable signal on T2-weighted images and thick peripheral enhancement after contrast administration Fig.  1, 2, 44–6, 37.FTreatment of both epidermoid and dermoid cysts is surgical resection; recurrence is uncommon .CBAF1 gene. It is a polyostotic disorder characterised by incomplete intramembranous ossification of midline bony structures. It affects the skull, clavicles and eruption of teeth .Fig.Fig48].FTreatment includes surgical excision and radiotherapy postoperatively in non-resectable tumours. Chordomas have a high rate of recurrence and, as a result, post-treatment follow-up imaging is necessary , 50.Chondrosarcomas are slow growing malignant lesions accounting for 6% of the skull base neoplasms. They arise from remnants of embryonal cartilage, endochondral bone or primitive mesenchymal cells. The typical location of this tumour is off-midline, centred at the petro-occipital fissure/synchondrosis –52.On CT, an osteolytic soft tissue mass is seen at the petro-occipital fissure with the characteristic chondroid matrix calcification (“rings and arcs”) and sharp non-sclerotic transition zone. On MRI, this tumour has low to intermediate signal on T1-weighted images; it has high signal on T2-weighted images; there may be interspersed foci of low signal due to chondroid matrix calcification. Post-contrast images show heterogeneous enhancement, classically with whorls of enhancing lines within the tumour matrix Fig.  50–52].–52.50–52The prognosis depends on the extent of the tumour at diagnosis and histological pattern. Conventional chondrosarcomas have a slow growth pattern and a good prognosis. The mesenchymal and dedifferentiated subtypes have an aggressive behaviour. High-grade chondrosarcomas metastasises to lungs and bones more frequently . SurgicaThe spectrum of systemic conditions that can affect the skull is broad and can be difficult to diagnose since each tend to have diffuse involvement of the skull. Of these, three systemic conditions are often encountered in clinical practice and familiarity with their main features is key to diagnosis.The skull changes of patients with chronic anaemia are due to red marrow hyperplasia and consist of widening of the diploic space, and thinning and obliteration of the outer table. Before diploic widening, a coarse granular or stippled pattern can be seen in the upper parietal region. When the hyperplastic marrow perforates or destroys the outer table, fine bony spicules perpendicular to the outer table are seen, giving the typical “hair-on-end” appearance. This can be seen with thalassaemia, sickle cell disease and iron-deficiency anaemia Fig.  5, 53, , 53, 54.Renal osteodystrophy refers to the complex findings seen in the setting of chronic renal insufficiency. Chronic renal failure alters bone metabolism by multiple mechanisms. Phosphate retention and decreased vitamin D conversion leads to hypocalcaemia, which in turn, stimulates the production of parathyroid hormone, causing bone resorption –57.The various skeletal features of renal osteodystrophy have been well documented including generalised demineralisation, thinning of the cortical bone, coarsening of the trabeculae, subperiosteal resorption, bone cysts and pathological fractures .In patients with chronic renal insufficiency, imaging shows diffuse increase in bone density, a finding that is seen more often in the axial skeleton, which has more trabecular bone than cortical bone. It is thought that this diffuse osteosclerosis may be due to the anabolic effect of parathyroid hormone .In the skull, there is diffuse bone thickening with loss of distinction between the inner and outer tables, and granular de-ossification of the skull due to lytic foci interspersed within normal bone, giving the appearance of “salt and pepper” or “pepper pot” skull Fig.  55–57].–57.55–57Osteopenia is a condition characterised by decreased bone mineralisation. It may arise when bone formation is inadequate or when bone resorption exceeds bone formation. It has multiple causes including congenital, toxic, metabolic and idiopathic. In osteopenia, there is loss of both cortical and trabecular bone, giving rise to a heterogeneous appearance on imaging. In contrast to renal osteodystrophy, the distinction between the inner and outer tables is preserved Fig.  57]..57].Skull “pseudolesions” include arachnoid granulations, prominent venous lakes, hyperostosis frontalis, thinning of the parietal bones and surgical burr holes. It is important to recognise these entities, so as to not mistake them for true pathology.Arachnoid granulations, also known as pacchionian granulations are projections of enlarged arachnoid villi into the calvaria or dural venous sinuses. They are involved in the filtration of cerebrospinal fluid (CSF) from the subarachnoid space to the venous system. Histologically, they are composed of dense collagenous connective tissue admixed with clusters of arachnoid cells and a network of delicate vascular space filled with CSF from the contiguous subarachnoid space , 58.The prevalence of arachnoid granulations increases with age. They normally measure a few millimetres, but can grow to fill and dilate the dural sinuses with expansion of the inner table of the skull and are then called “giant arachnoid granulations”. They can occur along any dural venous sinus, but are most commonly along the transverse sinuses, particularly within the middle and lateral portions. The second most common location is along the superior sagittal sinus , 58.On CT, they present as sharply marginated, hypoattenuating structures in close association with a dural venous sinus. On MRI, they generally appear hypointense or isointense to the brain parenchyma on T1-weighted images and hyperintense on T2-weighted images Fig. . They apVenous channels consist of apertures in the skull through which emissary veins pass, connecting the venous sinuses of the dura mater with veins external to the skull. They look like serpiginous or linear lucencies with sclerotic borders through the skull, and are, therefore, occasionally mistaken for sutures or fractures .Enlarged veins within the diploic space are known as venous lakes, corresponding to round or oval lucent foci, frequently along the inner table of the skull Fig. . These nHyperostosis frontalis interna is a benign condition which presents as irregular thickening of the inner table of the frontal bone Fig. . AlthougBilateral parietal thinning is an uncommon condition, with prevalence of 0.25–0.8%. This condition is thought to be due to non-progressive congenital dysplasia of the diploe. Parietal thinning is more common in women than in men. The characteristic site of bilateral parietal thinning is the area between the sagittal suture and parietal prominence. Imaging features in the skull include symmetric thinning of the bilateral parietal bones involving the outer table and diploe, giving a scalloped appearance Fig. . In caseBurr holes appear as well-defined defects in the inner and outer tables of the skull vault on CT or plain radiographs. On contrast-enhanced MRI, the margins of the burr hole usually show enhancement .As seen, a wide spectrum of benign and malignant neoplasms can involve the calvarium. Benign tumours have well-defined borders with a narrow transition zone and sclerotic margins. On the other hand, malignant tumours have poorly defined margins, a wide transition zone, aggressive periosteal reaction, and lead to dramatic bony destruction with intracranial or extracranial extension. Benign lesions comprise fibrous dysplasia, osteoma, Langerhans cell histiocytosis, venous vascular malformation (formerly known as haemangioma) and Paget disease, as well as several others. Malignant lesions typically affecting the skull are metastases, multiple myeloma, osteosarcoma, chordoma and chondrosarcoma. Systemic diseases may also affect the skull as shown with chronic anaemia, renal osteodystrophy and osteopenia. It is also important to not mistake normal variations of the skull as pathology.This article has demonstrated that CT and MRI have complementary roles in determining the nature of skull lesions. The recognition of the radiological appearance of calvarial lesions in association with the age, clinical history and symptoms of the patient is essential for the diagnosis, which ultimately impacts management. Some lesions can be left alone with no follow-up, while others need aggressive treatment with resection, radiation and/or chemotherapy.


Tracheal tumors are rarely diagnosed in veterinary medicine and the majority of tracheal neoplasia reported in adult dogs are malignant. Intratracheal lipoma has not been previously reported in the veterinary literature.A 7-year-old Briard dog was evaluated for inspiratory dyspnoea and an inspiratory wheeze. Cervical radiographs and tracheoscopic examination revealed an intratracheal mass that was surgically removed. The dog has been asymptomatic after the surgery.Based on histopathology, the mass was diagnosed as lipoma. To the authors‘ knowledge, this is the first published report of an intratracheal lipoma in the veterinary literature. Tracheal neoplasia is infrequently encountered in domestic animals and humans; the majority of which are malignant , 2. The Tracheal tumours reported in dogs and cats include adenocarcinoma, carcinoma, extramedullary plasmacytoma, leiomyoma, fibrosarcoma, mast cell tumour, rhabdomyosarcoma and squamous cell carcinoma –10. In aDogs with an obstructing tracheal tumour typically present with clinical signs of inspiratory dyspnoea, panting, cough, auscultatory wheeze or collapse . A trachIntraluminal tracheal lipoma has not been previously described in the veterinary literature. This case describes the successful surgical management of an endotracheal lipoma causing upper airway obstruction in a dog.A 7-year-old, 32 kg, neutered female Briard dog presented with inspiratory dyspnoea and an audible inspiratory wheeze particularly during exercise and after eating. The symptoms had been gradually worsening for a period of 3 months. There had been no cough or nasal discharge.Mild inspiratory dyspnoea and increased inspiratory sounds during tracheal and laryngeal auscultation were noted at rest. Symptoms progressed to moderate to severe inspiratory dyspnoea under stress and an audible inspiratory wheeze became evident. Serum biochemistry revealed raised alkaline phosphatase activity ; other values were within normal range.Left lateral cervical projection radiograph and radiographs of the thorax  were obtained. The dorsoventral projection included the caudal cervical trachea. In the left lateral cervical radiograph, a soft tissue opaque crescent shaped mass with long side dorsally was identified in the tracheal lumen at the level of the 5th and 6th cervical vertebrae Fig. . The masTracheoscopy and bronchoscopy were performed under light anaesthesia with butorphanol  and propofol  with a 4.9-mm flexible endoscope (Olympus GIF-N180). An approximately 3 cm long intraluminal mass originating from the dorsal membrane of the trachea was detected approximately 11–12 cm from the larynx  and acepromazine  and anaesthesia was induced with propofol , ketamine  and midazolam . Anaesthesia was maintained with a constant-rate infusion of fentanyl . Intubation was performed under endoscopic guidance and an endotracheal tube was placed such that its cuff was distal to the mass. Cefazoline  was given intravenously 30 min before incision and every 90 min thereafter.The dog was placed in dorsal recumbency and neck in extended position. Before the incision, the surgical area was infiltrated with lidocaine . The cervical trachea was approached via ventral midline approach. The centre of the incision was approximately 10 cm from the larynx. The dissection was continued along the left side of the trachea as the endoscopic examination suggested that the mass extended more to the left side of the dorsal membrane. Oesophagus, nerves and vessels were avoided during the dissection. A stay suture was placed around the tracheal cartilage to facilitate rotation of the trachea to the right. The tracheal mass was localised using palpation and a longitudinal incision was made to the dorsal membrane next to the tumour margin. On the right side, the mass was attached to the dorsal membrane and on the left side to the site where the dorsal membrane joins cartilage. The tumour was resected from the dorsal membrane with narrow margins of healthy looking tissue. The right-sided dorsal membrane was sutured to the cartilage edges and annular ligaments on the left side using simple interrupted 3-0 polydioxanone  appositional sutures placed 2–3 mm from the wound edge. The last sutures were preplaced before tightening. Closure of the wound was performed in a routine fashion. On macroscopic evaluation the mass resembled fat tissue. The mass was formalin fixed and processed for histology at which it was identified as a lipoma (Fig. The dog was hospitalised for 24 h after surgery for postoperative observation. Respiratory signs were relieved immediately after surgical removal of the tumour and postoperative recovery was uneventful.At the control visit 6 weeks after the operation, the dog was free of symptoms and there were no abnormal findings on physical examination. In the control endoscopic examination, the surgical area had healed well with minimal scar tissue formation and no tracheal stenosis Fig. . The ownTo our knowledge this is the first reported case of canine tracheal lipoma. The finding is exceptional as the majority of tracheal tumours reported thus far in both veterinary and human literature have been malignant. Lipomas are among the most common tumours of the skin and soft tissue in dogs; lipomas in other parts of the canine respiratory tract such as the lungs, larynx and epiglottis have been described in case reports –23.Preoperative cytological or histopathological diagnosis of tumour type is essential for the prognosis and treatment of the patient; it affects the treatment modality chosen as well as determines surgical margins necessary for successful removal . In our Staging and evaluation of tumour invasion provides important prognostic information and aids surgical planning. In the described case, pulmonary nodules or enlarged lymph nodes were not detected in thoracic radiographs. However, it has been shown that CT is more sensitive in detecting pulmonary metastasis than radiography and in our case a CT examination would have provided valuable information on possible lymph node or lung metastasis, enabled sampling of these lesions and would have displayed the extent of the tumour outside endoscopically visible trachea –28. AddiIn previous reports, canine tracheal tumours have been excised by endoscopic snaring of the tumour, blunt dissection or tracheal resection and anastomosis , 24. In This report adds lipoma as a differential diagnosis for an intraluminal tracheal tumour in dogs and shows that surgical excision may be curative.


Sudden, transient reduction in the blood flow especially in the “watershed” regions of the colon can lead to intestinal ischemia causing a decrease in the delivery of oxygen and nutrients to the intestinal wall. Patients with ischemic colitis often have elevated white blood cell counts, serum lactate, and serum amylase levels. Colonoscopy can confirm the diagnosis of ischemia and the findings include edematous, friable mucosa, erythema with interspersed pale areas, scattered hemorrhagic erosions or linear ulcerations. A single, linear ulcer running along the anti-mesenteric colonic wall, "single-stripe sign"- favors the diagnosis of ischemic colitis. Management of mild and moderate colonic ischemia includes supportive care with bowel rest, gastric suction for associated ileus, fluid-electrolyte balance, and broad-spectrum antibiotics. Patients with severe colonic ischemia may require abdominal exploration and colectomy. Ischemic colitis is the most common form of vascular injury to the gastrointestinal tract . The mosA 62-year-old female with a past medical history of tobacco abuse, hypertension, constipation, and chronic headaches managed by ibuprofen, presented to the emergency room with complaints of diffuse abdominal pain and bright red blood per rectum since two days. On physical examination, the patient was afebrile, the abdomen was soft, non-tender, with normal bowel sounds. The rectal exam was unrevealing except for bright red blood on the gloved finger. Laboratory studies showed hemoglobin of 15 g/dl, white blood cell count of 23,700/µl with normal serum lactate, amylase, and lipase levels. Colonoscopy showed discontinuous areas of non-bleeding ulcerated mucosa with no stigmata of recent bleeding in the sigmoid colon and descending colon for a total of 20 cms, consistent with the “single-stripe sign”, characteristic of colonic ischemia Figure . FurtherThe patient was discharged on a seven-day course of oral ciprofloxacin and metronidazole, managed for constipation with polyethylene glycol, and was advised to quit smoking and to avoid non-steroidal anti-inflammatory drugs.Sudden, transient reduction in the blood flow especially in the “watershed” regions of the colon can lead to intestinal ischemia causing a decrease in the delivery of oxygen and nutrients to the intestinal wall . The etiMarston et al. first coined the term ischemic colitis in 1966 to characterize the clinical syndrome associated with vascular compromise to the colon . ZuckermA plain abdominal radiograph is frequently nonspecific unless there is advanced ischemia, which shows pneumatosis or distension. Computed tomography (CT) of the abdomen with contrast can show edema and thickening of the bowel wall in a segmental pattern, irregular bowel contour, inflamed mesentery with stranding of the fat, or presence of free peritoneal fluid. Management of mild and moderate colonic ischemia includes supportive care with bowel rest, gastric suction for associated ileus, fluid-electrolyte balance and broad-spectrum antibiotics. Patients with severe colonic ischemia require abdominal exploration and colectomy -5.The increase in longevity of the population has brought about a consequent increase in the incidence of colonic ischemia. Patients commonly present with crampy abdominal pain and rectal bleeding. Colonoscopy is the gold standard for diagnosis. Left-sided lesions in the distribution of the inferior mesenteric artery are more common, while right-sided lesions portend a worse prognosis with a higher risk for surgical intervention. In the majority of patients, treatment is supportive with bowel rest and intravenous fluids.


Primary lymphoma that arises de novo from the central nervous system (CNS) is most commonly a non-Hodgkin's B-cell lymphoma and by definition lacks the presence of disease outside the CNS. It demonstrates a characteristic imaging appearance on computed tomography (CT) and magnetic resonance imaging (MRI) exams related to its inherent hypercellularity. On CT, primary CNS lymphoma (PCNSL) demonstrates a hyperdense appearance; on MRI, it commonly demonstrates restricted water diffusion on diffusion-weighted sequences and homogeneous enhancement on post-contrast sequences. We present a case of primary CNS lymphoma in an immunocompetent patient with progressive necrosis and loss of restricted diffusion on diffusion-weighted imaging (DWI) with an atypical enhancement pattern. We further provide a review of the literature regarding the CT and MRI appearance of primary CNS lymphoma and discuss the role of immune status in determining the imaging characteristics of this disease process. Lymphoma may occur as a de novo primary central nervous system (CNS) lymphoma (PCNSL) with absence of disease outside the CNS or as a secondary CNS lymphoma (SCNSL) related to systemic disease and CNS metastasis -2. Both Whereas SCNSL typically involves the skull and dura, PCNSL much more commonly involves the brain parenchyma and has a characteristic imaging appearance in the immunocompetent patient population related to the tumor’s inherent hypercellularity, high nuclear/cytoplasmic ratio, and disruption of the blood-brain barrier. On non-contrast computed tomography (CT), PCNSL is typically hyperdense. When magnetic resonance imaging (MRI) is performed, PCNSL demonstrates diffusion restriction on diffusion-weighted imaging (DWI) and avid enhancement with gadolinium administration. PCNSL has a predilection for the deep structures of the brain and typically demonstrates a periventricular or perivascular location. Two-thirds of tumors present as a solitary mass. The presence of necrosis and hemorrhage with PCNSL is uncommon unless the patient is immunocompromised ,4-5.A 50-year-old male with a past medical history of hypertension and heavy alcohol use in the past (reportedly abstinent for the preceding four months) presented with one month of recurrent and progressive dizziness and worsening memory impairment. The patient also endorsed anomic aphasia (word finding difficulty), acalculia , and confusion. Neurologic exam demonstrated 3+ hyperactive lower extremity reflexes, a positive Babinski sign bilaterally, decreased lower extremity vibratory sensation, and conjugate nystagmus on lateral gaze with horizontal diplopia. The remaining neurologic exam was unremarkable. 9/L and a normal thiamine level; remaining laboratory findings were within normal limits. A lumbar puncture with cerebrospinal fluid (CSF) analysis was unremarkable. Non-contrast head CT followed by serial MRI examinations of the brain without and with intravenous (IV) gadolinium was performed for further assessment.Based on presenting signs and symptoms, the patient was tentatively diagnosed with Wernicke-Korsakoff syndrome. Laboratory testing, including comprehensive metabolic panel, complete blood count, thyroid stimulating hormone, HIV, and thiamine level were performed. Laboratory findings revealed an elevated white blood cell count of 12.6 × 10Initial non-contrast CT of the head demonstrated a well-demarcated area of slightly hyperdense attenuation with surrounding edema centered in the bilateral parietal lobes and splenium of the corpus callosum extending across the midline. There was no hemorrhage or mass effect Figure .Based on the head CT findings and clinical presentation, a follow-up pre and post-contrast brain MRI was performed and demonstrated a mass in the subcortical white matter in the bilateral parietal lobes and splenium of the corpus callosum with extension across the midline and surrounding vasogenic edema. The mass was isointense on T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences. DWI with a B-value of 1000 and corresponding apparent diffusion coefficient (ADC) map demonstrated mild diffusion restriction. The post-contrast T1-weighted sequence demonstrated discontinuous areas of homogeneous enhancement. No associated mass effect, volume loss, or hemorrhage was present  was raised based on the follow-up imaging. The patient subsequently underwent a left occipital-approach stereotactic biopsy of the lesion. The specimen yielded sheets of large lymphocytes with open chromatin, nucleoli and high nuclear to cytoplasmic ratio consistent with diffuse large B-cell lymphoma. Inpatient treatment with chemotherapy was initiated. Post treatment brain MRI demonstrated a positive response to therapy with decreased volume of the lesion and resolution of the peripheral enhancement Figure .This case is unique for several reasons. Serial follow-up brain MRI exams demonstrate intercurrent lack of hypercellularity associated with the tumor as no restricted water diffusion on DWI was present at the three and five month intervals. A study by Haldorsen et al.reviewed the CT and MRI findings of 76 patients with biopsy-proven PCNSL and found 100% of their patients demonstrated either isodense or hyperdense attenuation of the tumor relative to white matter on non-contrast head CT .al.describe homogeneous contrast enhancement on MRI in 90% of patients in the non-AIDS population [The serial follow-up MRI exams performed in this patient who refused biopsy and surgical treatment also demonstrated an increasingly necrotic appearance of the tumor on T2-weighted imaging with internal areas of hyperintense signal intensity within the corpus callosum and biparietal deep white matter. This imaging appearance on MRI has been observed in AIDS-related PCNSL with many of the lesions exhibiting necrotic regions and more commonly a multifocal or disseminated appearance ,5,9. SubAtypical MRI appearance of PCNSL  in an immunocompetent patient is rare in the USA. This presentation is more common among patient with tumors who are positive for EBV -10. EBV-Given the imaging appearance on follow-up brain MRI exams, the question of whether this lesion could represent tumefactive demyelination (TDL) was also raised. Differentiating PCNSL from TDL may be extremely difficult in some patients due to the variability of clinical presentation and imaging findings . The lymHistologically, differentiating demyelination from PCNSL may also be challenging due to the fact the PCNSL may present in association with steroid-responsive multifocal demyelinating sentinel lesions, which histologically are indistinguishable from multiple sclerosis (MS), containing predominantly T-cell infiltrates and a few B cells ,11. Addi−6 mm2/s was the best indicator for differentiating TDL from atypical PCNSL (a sensitivity of 81% and specificity of 89%) [A few studies have tried to differentiate TDLs from PCNSLs using advanced MR imaging techniques. Two studies demonstrated a significantly higher ADC minimum in TDL than in PCNSL with one study demonstrating that ADC minimum with a threshold of 556 × 10 of 89%) -18.Another study showed a lower choline/N-acetylaspartate (NAA) ratio in TDLs than in PCNSLs, with a threshold for differentiation of 1.73 yielding sensitivity of 89% and specificity of 76%. In addition, non-contrast CT hypoattenuation of MRI enhancing regions was observed in 93% of TDL cases, but only 4% of primary brain tumors . One stuWe present an unusual case of PCNSL in an immunocompetent patient demonstrating a progressive, atypical imaging appearance on MRI. Findings help reinforce the protean appearance of PCNSL, which may occasionally lack the characteristic hypercellular imaging appearance on CT and MRI exams especially if left untreated. Review of the literature suggests the presence of necrosis and peripheral enhancement on MRI to be uncommon in the immunocompetent population and more commonly associated with EBV-positive tumors or in HIV positive patients. The lack of the typical imaging appearance of PCNSL should not dissuade one from the diagnosis, especially for a lesion located in the deep white matter or corpus callosum.


A 9-year-old spayed female dachshund presented with a large multilobular osteochondrosarcoma of the crania, with obliteration of approximately 70% of the surface area of the dorsal calvaria and intracranial extension. The mass was excised with histologically clean lateral bone margins (2–4 mm) and invasion at the deep margin. The resulting defect was reconstructed with a custom titanium plate. The patient recovered routinely and was asymptomatic until 7 months postoperatively. The patient developed intractable seizures 7 months postoperatively and was euthanized. Post-mortem examination showed tumor regrowth within the brain parenchyma. No abnormalities were seen associated with the plate. The patient-specific, custom additive manufactured titanium plate provided an excellent option for anatomic reconstruction and protection of the brain over a relatively large area with no complications noted. Various methods for pre-operative and intra-operative planning and reconstruction of extensive craniectomy have been described in dogs –4. This A 9-year-old, 7.7 kg spayed female dachshund was referred for large tumor of the dorsal calvarium first noted by the owner 3 years prior to presentation, with a marked increase in size in the last 6 months. Tumor diameter at presentation was 7.2 × 5.2 × 6.7 cm, with an asymmetric placement toward the left side . A coughSurgical excision with curative-intent bone margins was recommended. To obtain these margins, resection of the roof of the left and right frontal sinuses, and a large part of the medial wall of the left orbit was required. The resulting defect necessitated cranioplasty, ideally with a rigid implant. Due to the size of the tumor and the limitations of the surrounding anatomy, the window of visualization, for performing the craniectomy through the medial wall of the left orbit, was anticipated to be small. The ability to intraoperatively view and handle a sterile anatomic bio-model of the skull and tumor for reference was anticipated to facilitate successful and accurate preoperative planning and resection.The computed tomography (CT) scans of the patient were exported as Digital Imaging and Communications in Medicine (DICOM) format and the images were imported into a DICOM viewer . A boarded veterinary surgical oncologist and radiologist assessed the scans and reached an agreement on tumor margins in Osirix MD. The DICOM files were then imported into Materialise Mimics  and the stereolithography (STL) file was exported using Materialise 3-matic . An anatomic bio-model of the patient and tumor was printed using the J750 polyjet 3D printer .A custom titanium plate was designed and printed for the patient as described by James et al. . BrieflyA cutting guide was then created to provide a template for surgical resection. First, the tumor margins identified in Osirix MD were imported into ANSYS SpaceClaim . A 3D spline curve was fit to the data points which represented the tumor margin. The reconstructed skull STL and the tumor margin curve were imported into Geomagic Freeform . The guide was designed to fit to the interface between the skull and tumor surfaces with a positive profile to be used for the template. The tumor margin curve was thickened into a 10 mm diameter 3D round tube and subtracted from the skull creating a model of the skull with a 5 mm margin tumor resection. The cutting guide was created by subtracting the intact skull STL from the 10 mm 3D round bar. The resulting shape was divided into four sections. The cutting guide segments were printed for intraoperative use.The STL models of the cut skull, 5 mm margin tumor resection, tumor, and surgical cutting guides were 3D printed using the J750 polyjet printer . The titanium plate was autoclave sterilized under standard conditions. The guide and skull pre- and post-planned craniectomy, were H2O2 sterilized with standard protocols for use in the operating room.2 and level of neuromuscular blockade (train of four) was performed. Surgical excision of the mass was performed as per a standard craniectomy approach with modifications to allow for access to the ventral orbit [Following construction, printing and sterilization of the implant, the patient was admitted for surgery. The patient was pre-medicated with dexmedetomidine and atropine. Anesthesia was induced with remifentanil and propofol and maintained with remifentanil and propofol constant rate infusion (CRI). Neuromuscular blockade was initiated with an atracurium CRI and positive pressure ventilation on 100% oxygen provided. Cefazolin was administered prior to skin incision. Phenylephrine was administered to control blood pressure. Continuous monitoring of EKG, SpO2, esophageal temperature, end tidal COal orbit . BrieflyThe patient made a routine recovery from surgery and was maintained postoperatively on intravenous fluid therapy, fentanyl (1–6 ug/kg/hr IV CRI) and cefazolin (22 mg/kg IV Q8). Fluorescein staining of the left eye the evening of surgery was negative for injury, and palpebral, menace and pupillary light reflexes were normal. The dog was neurologically appropriate following anesthesia recovery and was weaned off of analgesics over 2 days postoperatively and discharged 3 days postoperatively on gabapentin 50 mg PO Q12 and clavaseptin 62.5 mg PO Q 12 × 14 days. The tubes in the frontal sinuses were removed prior to discharge and the stomas allowed to granulate by second intention healing. No subcutaneous emphysema was noted at any point. Mild serosanguinous nasal discharge was noted for the first 5 days postoperatively which then resolved. Incisional healing was routine. A CT scan was repeated under sedation 14 days postoperatively, and showed good skull defect coverage and alignment of the implant . HistopaThe patient continued to have no evidence of clinical signs associated with the craniectomy or cranial plate until 6 months postoperatively. At that time, focal seizures were noted. Advanced imaging was declined and treatment with phenobarbital 5 mg/kg resulted in control of seizures until 7 months postoperatively when the patient experienced 4 seizures over 3 days and was presented in status epilepticus. Humane euthanasia was elected due to a progression of clinical signs and an autopsy was performed.Grossly, the titanium plate was well-placed, surrounded by a granulation tissue bed with granulation tissue filling the holes of the titanium plate. Suppurative sinusitis  that culThis report demonstrates the successful use of a custom additive manufactured titanium plate in a dog. Several implants are available for reconstruction following craniectomy –4. TitanIn addition to a custom plate, 3D printing was utilized in this case to create an anatomic bio-model of the patient and a cutting template. The intraoperative availability of a sterile, to-scale model of the tumor and proposed craniectomy provided several advantages . For thiSince the procedure was performed in a single-stage it was important that the resultant craniectomy defect was precise to ensure adequate margins for aspects of the mass that were not visible on the surface and to ensure the implant would fit for reconstruction. Cutting guides, or templates, have been described for a number of surgical procedures in both human and veterinary surgery –14. TempAny use of surgical implants carries a lifelong risk of implant-associated infections. In this case, the craniectomy involved removal of both a large portion of the frontal sinus and calvarium, including the cribriform plate, resulting in a communication between the sinonasal and calvarial cavity. Reconstruction of this division was not possible and porcine SIS was placed to provide a pseudo-barrier and to decrease the risk of adhesions. Antimicrobial prophylaxis was provided for 2 weeks and no evidence of clinical infections were noted. At the time of post-mortem examination, approximately 7 months postoperatively, there were signs of sinusitis but there was no indication of any active intracranial infection. In humans, infection in patients with cranial implants has been reported in 7–16% –17. It iIn this case, the patient developed status epilepticus and was euthanized 7 months postoperatively. Initially the differential diagnoses for seizures included infection, adhesions or hydrocephalus. Given the presence of a complete histologic lateral bone margins and no evidence of intradural invasion at the time of the initial surgery, recurrence of the tumor within the dural tissue was not expected. Absence of a deep margin on the original histopathology report was interpreted as disease extension into the calvaria rather than infiltration of the intra-calvarial soft tissues. However, based on the autopsy findings, it was determined that the cause of the seizures was the presence of a large, intracerebral mass compressing and replacing most of the right frontal cortex, causing significant midline shift. The tumor appeared to be extending from the fibrovascular tissue abutting the brain and was contained beneath the porcine SIS and growing into the brain tissue. The histologic features of the regrowth compared to the initial surgical excision  have sliTo the authors' knowledge, this is the first report of recurrence of MLO in the soft tissues surrounding the brain.This case report demonstrates the successful use of 3D printing forcreation of a surgical cutting guide and custom additive manufactured titanium plate in a dog following single-stage craniectomy and cranioplasty. Based on our experience, this technique appears feasible with excellent cosmesis and limited postoperative complications. Local recurrence should be considered, as with any case of tumor resection, and soft tissue margins may be more important than previously reported in cases of MLO in dogs.


The purpose of this article is to review calcified or ossified benign soft tissue lesions that may simulate malignancy. We review the clinical presentations, locations, imaging characteristics, and differential diagnostic considerations of myositis ossificans, tophaceous gout, benign vascular lesions, calcific tendinopathy with osseous involvement, periosteal chondroma, primary synovial chondromatosis, Hoffa’s disease, tumoral calcinosis, lipoma with metaplasia, calcifying aponeurotic fibroma, calcific myonecrosis, ancient schwannoma, and Castleman disease. Many patients are referred to the radiology department for evaluation of a soft tissue lesion in daily practice. The vast majority of soft tissue lesions are benign, with a very good outcome after resection . MalignaDifferentiation between calcifications and ossification is very important in making the correct  diagnosis. Radiography is usually the initial imaging modality by which soft tissue calcifications and ossification are detected. Calcifications normally appear as mineralized densities, whereas mature bone shows an outer cortex and inner trabecular pattern Fig.  3]. CT . CT 3]. Myositis ossificans is a benign ossifying soft tissue mass typically occurring within skeletal muscle . Of noteGout is a crystal arthropathy resulting from monosodium urate crystal deposition in and around the joints. Monosodium urate crystals can precipitate with calcium when extraarticular and not in solution (intraarticular). Transplant recipients, females, and elderly people in particular can develop gouty tophi as an initial manifestation of their disease . TophaceVenous malformations are the most common peripheral vascular malformation. They can occur anywhere, but are usually located in the head and neck (40% of cases), trunk (20%), and extremities (40%) . Venous Calcific tendinopathy is a common, usually self-limiting disorder due to deposition of calcium hydroxyapatite within tendons, usually of the rotator cuff. The adjacent bone may occasionally be involved –23, whicPeriosteal chondroma, also known as juxtacortical chondroma, is a rare benign chondral tumor arising from the periosteum , 25. PrePrimary synovial chondromatosis is an uncommon benign neoplastic process with development of intrasynovial cartilage nodules in a joint, tendon sheath, or bursa . These nHoffa disease is a syndrome of impingement and probably caused by acute or repetitive trauma leading to hemorrhage in Hoffa’s fat pad , 31. TheTumoral calcinosis is a rare hereditary disease caused by metabolic dysfunction of phosphate regulation associated with massive periarticular calcinosis . Black pLipoma with metaplastic bone  is a rare variant of lipoma in which both mature adipose tissue and mature lamellar bone are present , 39, 40.Calcifying aponeurotic fibroma is a rare benign but locally aggressive fibroblastic tumor that most commonly affects the deep volar fascia, tendons, and aponeuroses of the hands, followed by the feet . Less frCalcific myonecrosis is a rare posttraumatic entity, in which a muscle is replaced by a fusiform mass with central liquefaction and peripheral calcifications , 52. It Ancient schwannomas are long-standing, slow-growing schwannomas that show advanced degeneration. They are usually located deep in the head and neck, chest, retroperitoneum, pelvis, and extremities of elderly patients . BecauseCastleman disease is an uncommon benign nonclonal lymphoproliferative disorder, which may present as a localized or multicentric form. The localized form typically occurs earlier in life (3rd and 4th decades) and may be asymptomatic. The multicentric form occurs later in life (5th and 6th decades) and systemic inflammatory symptoms are common , 57. AltThe typical clinical features, specific imaging features, and main differential diagnostic considerations of calcified or ossified benign soft tissue lesions that may simulate malignancy are summarized in Table There is a wide spectrum of calcified or ossified benign soft tissue lesions that may simulate malignancy. Knowledge of their clinical presentations, locations, and imaging characteristics is essential to make a correct diagnosis or to narrow the differential diagnosis, and to recommend justified further imaging or tissue sampling when a certain diagnosis in terms of benignancy or malignancy cannot be made.


Meningiomas are the most common benign intracranial tumors accounting for up to 30% of non-glial tumors of the central nervous system (CNS); on neuroimaging studies, they usually appear as a lobular, extra-axial mass with well-circumscribed margins mostly located in the parasagittal aspect of the cerebral convexity. On magnetic resonance imaging (MRI) of the brain, meningiomas are typically isointense to hypointense relative to grey matter in the T1-weighted sequence and isointense to slight hyperintense relative to grey matter on the T2-weighted sequence with avid homogeneous enhancement after contrast administration. A thin linear enhancement along the dura infiltrating away from the lesion, known as the dural tail sign, was once thought to be a pathognomonic feature of meningiomas, but this non-specific sign can also be seen in other meningioma-like lesions. Several benign and malignant pathologies may mimic some of the neuroimaging characteristics of meningiomas; among them dural metastases of lymphomas. When approaching a patient with suspected meningioma, close attention to the neuroimaging features may help distinguish them from meningioma-like lesions. Here we present the case of a woman with CNS involvement of non-Hodgkin lymphoma that presented with a dural mass resembling the neuroimaging characteristics of a meningioma.  Secondary central nervous system (CNS) involvement of aggressive systemic non-Hodgkin lymphomas occurs in less than 5% of diffuse large B-cell lymphomas (DLBCL) cases -2. At thA previously healthy 77-year-old woman, with a one-month history of headache and left arm weakness presented to the emergency department with nausea, vomiting, and abdominal pain for the past three days. On admission, she was alert; the neurological examination was relevant for left upper motor neuron facial paralysis and mild ipsilateral arm weakness  scale 4/5). An abdominal examination revealed a round palpable mass in the right lower quadrant. Blood workup, including a full blood count, serum electrolytes, lactate dehydrogenase, liver, and kidney function tests, were all within the normal range. Testing for human immunodeficiency virus (HIV) and hepatitis C antibodies were negative. An abdominal computed tomography (CT) showed a contrast-enhancing ill-defined appendicular mass Figure . Three dAs part of the seizure investigation, an electroencephalogram (EEG) was performed; relevant findings included an encephalopathic rhythm within the delta-theta range without epileptiform activity. MRI of the brain showed an extra-axial right frontotemporal dural mass with heterogeneous gadolinium enhancement and perilesional edema Figures -1D.Treatment with levetiracetam, midazolam, and dexamethasone for brain edema was started. Under the suspicion of meningioma, she underwent surgical resection of the dural mass without any complications; also colonoscopic biopsies of the appendicular mass were taken. Histologic analysis of both masses showed diffuse infiltration of large lymphoid cells; in immunohistochemistry, the large lymphoid cells were positive for cluster of differentiation 20 (CD20), B-cell leukemia/lymphoma 2 (BCL-2), BCL-6, and multiple myeloma oncogene 1 (MUM 1); and negative for CD3, CD10, and C-MYC, findings consistent with non-germinal center DLBCL (Figure Secondary CNS lymphoma may present as a dural-based lesion mimicking meningiomas . On MRI,When approaching a patient with a suspected meningioma, close attention to imaging features may help distinguish them from meningioma-like lesions. The distinction between meningioma and meningioma-like lesions is essential due to distinct changes in therapy depending on tissue-based pathology.


Adenomatoid odontogenic tumor constitutes an uncommon benign odontogenic tumor which is well-known as “two-thirds tumor” . Larger part of these present as intra - osseous tumors while peripheral counterparts are extremely rare. Peripheral adenomatoid odontogenic tumor is a unique entity which generally presents as a slow growing gingival swelling with minimal bone involvement. This often leads to its erroneous diagnosis as a simple gingival lesion and the real diagnosis is only revealed after its microscopic evaluation. It exhibits a marked predilection for maxillary gingiva of incisor region and most commonly affects the younger females.We report a case of 25 years old female patient of African ethnicity who presented with a 2 × 2 cm mass attached to the left mandibular gingiva in cuspid- bicuspid region which is an unusual site for AOT. It was accompanied by slight bone loss. With the differential diagnosis of gingival epulis and peripheral ossifying fibroma; surgical excision was performed. The light microscopic examination of the specimen aided the final diagnosis of Adenomatoid odontogenic tumor with the histopathological features identical to its intra osseous counterpart.In this case, the tumor is present on the mandibular gingiva in a 25 years old patient which is an atypical location and age for this tumor; also, the only individual case reported in an African patient. Only, a meager number of peripheral adenomatoid odontogenic tumor cases have been logged so far with majority of them occurring in maxillary gingiva. Furthermore, an ambiguity still prevails regarding its true origin and possible biological course. Hence, reporting of similar cases should be encouraged to facilitate the better understanding of its varied epidemiological details and clinical presentation. The term Adenomatoid odontogenic tumor (AOT) was given by Philipsen and Birn in 1969. It has described by numerous authors under diverse terminology like “adamantoma”, “epithelial odontome”, “cystic adamantoma”, “adenoameloblastoma”, “tooth germ (or chorioblastomatous) cyst of the jaw”, “epithelial tumors associated with developmental cysts of the maxilla” and several more dating from 1877 . This maAOT is a relatively rare distinct odontogenic neoplasm accounting for 2.2–7.1% of all odontogenic tumours. It constitutes about 1.2% of all odontogenic tumors (OTs) in Caucasians and up to 9% of OTs in Black Africans. The three clinicopathological variants of AOT are: follicular type, extrafollicular type and peripheral variety. Follicular and extrafollicular variants account for 97.7% of all the AOTs and are intrabony tumors while peripheral type is the rarest of them all constituting only 2.3% of all AOTs –12. The Similar to the central AOT, the subject of histiogenesis of PAOT also remains unsettled. Two theories have been proposed in regard to the origin of PAOT presenting as gingival mass. On one hand, PAOT with no to minimal bone loss is suggestive of its de novo origin; on the other hand, notable bone involvement can be indicative of its origin as tumor arising intraosseously that is eventually pushed peripherally by an erupting tooth. The present case belongs to the former category and the latter type has been identified as “Hybrid variant” .We report the first case of PAOT presenting as a gingival epulis in a Black African female patient with unusual clinical presentation.A 25 years old female patient of African ethnicity was referred to the Department of Oral and Maxillofacial Surgery, Ayder Referral hospital (Ethiopia) with the chief complaint of a mandibular gingival mass of two years duration. On general examination, the patient was apparently healthy. The medical history and family history were insignificant. No notable findings were recorded on extra-oral examination.Intra – oral examination revealed a solitary, well defined, roughly oval shaped gingival mass arising from the attached and free labial gingival margin covering two thirds portion of the crown of teeth 33 and 34 Fig. . It was Based on the clinico-radiographical findings, clinical diagnosis of pyogenic granulomas was established with differential diagnosis of peripheral ossifying fibroma, peripheral giant cell granuloma and fibrous epulis. The rare differential diagnosis include benign connective tissue tumors and peripheral odontogenic neoplasms.Following the routine blood examinations, the lesion was removed in toto under local anesthesia. The excised mass was sent for histopathological examination.Grossly, the specimen was roughly spheroidal in shape measuring 2 × 2 cm approximately and covered by a capsule with soft to firm consistency. Cut section revealed grayish - white appearance with minute hemorrhagic areas.The haematoxylin and eosin (H&E) stained sections were examined microscopically. The tumor mass was chiefly composed of varied proportions of spindle/polyhedral, cuboidal and columnar cells arranged in multiform patterns with a few areas showing cystic degeneration. Spindle/polyhedral cells were arranged in the whorled pattern; rosette formation was also observed. Cuboidal to tall columnar cells were arranged in the form of microcysts or ducts Fig. . ConvoluOn the basis of these classical features, the final diagnosis of peripheral adenomatoid odontogenic tumor was made.Among all the odontogenic tumors, PAOT represent 3.4% of all the tumors. Clinically, it presents as an asymptomatic, slowly but progressively growing gingival colored swelling with a strong predilection for maxillary anterior gingiva. The associated teeth might show some degree of mobility. Analogous to the central varieties, PAOTs also exhibit female predilection with male: female ratio ranging from 1:2 to 1:14 with the majority of cases occurring in younger age group (< 20 years) .We reviewed all the similar case reports available in the literature till date and their details have been summarized in Table Out of the twenty cases reviewed, 17 reveal anterior maxillary presentation indicating the clear predominance for this site followed by 3 cases in anterior mandible; no case has been reported in the posterior segment of the jaws Fig. . The ageSimilar clinical findings were reported by Chrcanovic BR and Gomez RS in 2019 who analyzed the data available on all the variants of AOT .In this report we present the case of PAOT in a 25 years old female patient. Its occurrence in third decade of age and mandibular premolar area involvement makes this case unique. Interestingly, a recent study conducted by Adisa AO et al. in 2016 suggested that there might be slight differences in demography of AOT from region to region and the “Two third tumor” notion generally ascribed to AOT may not be applicable to people of different race or ethnicity uniformly . Also, SAs is evident from the Table Radiographic features varied from negligible to a well defined radiolucency with sclerotic margins or slight erosion of the underlying alveolar bone cortex; minor arc shaped bone loss was seen in the presented case. X ray findings were not available for 8 cases.Special consideration was given to the CBCT (cone beam computed tomography) findings by Janavi et al. who observed numerous small specks of calcification scattered along the periphery of the lesion in the case of maxillary PAOT. The number, size and degree of calcifications present will influence the radiographic appearance of the lesion .Histologically, the tumor presents with myriad of arrays which are quite characteristic but it is not uncommon to find some Calcifying epithelial odontogenic tumor-like foci. Although present in varying proportions, the tumor is made up of a cellular multinodular proliferation of spindle, cuboidal, and columnar cells in a variety of patterns. Rosette formation, convoluted rows, duct like structures, eosinophilic material, and calcifications are some of its pronounced features. Also, it is invariably covered by a fibrous capsule of variable thickness , 8, 9.Conservative surgical excision with adequate margins is the treatment of choice. In this review, two cases had presented as recurrent tumors .Rightfully called as “master of disguise”, AOT bears a striking resemblance to other more commonly occurring oral lesions. PAOT is often misdiagnosed clinically as one of the simple gingival lesions such as pyogenic granuloma, peripheral giant cell granuloma, peripheral ossifying fibroma and focal mucinosis which often leads to overzealous treatment plans. Diagnosis of PAOT is only uncovered after histopathological investigation , 25, 29.To conclude, we presented the case of black female patient with PAOT having unusual age and site of occurrence; it was initially identified as pyogenic granuloma and treated for the same. No recurrence has been seen since one year follow up of the patient and it is still continued. The authors would like to focus on three important points: (1) Shifting demographic trends of PAOTs with the possible geographical variations (2) POTs should not be overlooked while formulating the differential diagnosis of gingival swellings (3) To reiterate the significance of ‘patient follow- up’ in such cases as the possible biological nature of PAOT is still uncertain, contrary to the innocent behavior exhibited by the other more common gingival lesions resembling PAOT.The data available on PAOT is clearly inadequate to determinate its distinctive aspects and acknowledge the emerging diversity in the clinical and biological course of this tumor. Hence, authors should be encouraged to report such rare entities.


The ureteric “rendezvous” procedure is an interventional procedure involving both uro-radiological and cystoscopic techniques to manage complex ureteric stenoses or fistulae. We present a case in which this procedure was utilised, with an unusual intra-procedural finding. Macroscopic visualisation of lipids within the urinary tract is an unusual finding at CT, and rarely seen at cystoscopy. The aetiology of lipiduria is varied; it may indicate the presence of unrecognised pathology, occur as a sequelae of trauma, or arise secondary to intervention. Understanding the patient's history is vital to determining the likely aetiology and significance of such a finding. An 86-year-old female underwent elective surgery for a locally advanced rectosigmoid tumour with synchronous cervical tumour. A Hartmann's procedure was carried out, with total abdominal hysterectomy and bilateral oophorectomy. At the time of surgery the distal right ureter was found to be involved, and distal ureterectomy and reimplantation over a ureteric stent were also performed. The stent was removed at 3 months. Surveillance CT imaging at 6 months demonstrated marked hydronephrosis  and hydrAfter failed attempts at antegrade stent insertion, temporising management was undertaken with nephrostomy, and the patient subsequently underwent cystoscopy as part of a combined endoscopic and uro-radiological rendezvous procedure to reinsert a ureteric stent.At cystoscopy, a surprising finding was made, with a large volume of viscous yellow fluid visualised lying anteriorly within the bladder , which hCorrelation with prior imaging revealed the presence of an intravesical fat-fluid level on CT carried out at 2 months post-operative, which had been overlooked in the report . This wa1 The procedure, whether antegrade or retrograde, requires the passage of a guidewire across the site of stricture and, as in our case, this may prove impossible. The ‘rendezvous’ procedure combines uro-radiological and endoscopic approaches, and often allows the negotiation of complex strictures or ureteric injuries with successful stent deployment, obviating the need for open surgical management or long-term percutaneous drainage.1 Whilst in the experience of our tertiary referral centre incidence of failure of either antegrade or retrograde stenting is rare, in such situations the rendezvous procedure provides a useful problem-solving management option.Use of ureteric stents to maintain or restore ureteric patency is a well-documented and relatively common procedure for the management of both ureteric strictures and injuries, and indwelling ureteric stents are better tolerated than percutaneous nephrostomy.1The procedure is undertaken under general anaesthesia in an oblique supine position. The uro-radiologist exchanges the patient’s nephrostomy  for a seAn intravesical fat-fluid level occurs with hydrophobic, low density fat molecules rising to the nondependent portions of the bladder above the denser normal bladder contents and seen on CT as a region of fat-density material (-60 to −120 Hounsfield Units) above the normal fluid-density (~1 Hounsfield Unit) content of the bladder, and best appreciated on sagittal reconstruction as in .Due to the contrast between fat and fluid, it is possible for the presence of fat in the vesicular cavity to be misinterpreted as gas. Although vesicular gas can be a sign of pathology, for example colovesical fistulation or trauma, it is more commonly seen following intervention such as urinary catheterisation. Use of lung or bone window pre-sets will allow fat and gas densities to be clearly distinguished, avoiding misinterpretation.2; and from fat deposition in the bladder wall, which represents an uncommon but normal variant CT finding.3Intravesical fat-fluid level should also be distinguished from the “fat triangle sign” which has been described as imaging evidence of extraperitoneal bladder rupture, in which extravasated urine outlines an area of fat4 Whilst beam hardening correction software can be used to minimise this artefact, in daily practice the use of increased window widths to review images  may allow improved visualisation of structures adjacent to metal hardware and reduce the effect of metal artefact.5Presence of hip prostheses, as in this case, can cause significant artefact on CT imaging due to photon starvation and beam hardening, with resultant reduced tissue contrast and spatial resolution, and associated increased risk of missed findings.5 often secondary to a fistulous connection between lymphatic channels and urinary tract.6 Causes of chyluria are broadly classified as parasitic and non-parasitic, and it is a rare entity in developed countries, where it is generally of non-parasitic cause.7The presence of fat within the vesicular cavity can be divided into two entities, chyluria and lipiduria. The former represents the presence of microscopic lipid and cholesterol-rich lymph in the urine. This forms a milky-white emulsion and is due to abnormal flow of lymph from abdominal lymphatic system to the urinary tract,7 It is a recognised sequelae of fat embolus,8 and has also been described following partial nephrectomy, renal transplant, and radiofrequency ablation of renal tumours.9 Whilst microscopic lipiduria may go unrecognised and therefore underreported, macroscopic lipiduria presenting as vesicular fat-fluid level at CT or, as in our patient, as visible fat within the bladder at cystoscopy, is more unusual. A number of cases have been reported, with differing aetiological hypotheses.Lipiduria refers to the presence of lipids in the urine, and can be a feature of nephrotic syndrome.10 The proposed mechanism is of acute increase in intra-abdominal pressure leading to migration of small fatty droplets from the extravesical compartment through the ruptured bladder wall. Soussan et al have reported a case of fat-fluid levels demonstrated in the renal calyces following urine extravasation as a complication of high-grade urinary tract obstruction and infection, proposing a mechanism whereby extravasated urine induces lipolysis of perirenal fat, the components of which enter the renal collecting system and collect in the non-dependent position.11 Hoven et al presented a case in which a vesicular fat-fluid level appeared coincidentally with resolution of previously identified perivesical fat necrosis in a patient following right hemicolectomy. No bladder injury was reported, and transmural migration of lipids is suspected.9Martinez-Moya et al report a case of intravesical fat-fluid level secondary to traumatic bladder rupture, which was noted on the patient’s CT imaging at presentation.Whilst it is possible that in our case a postsurgical lymphatico-ureteric or lymphatico-vesical fistula may have occurred, it is likely that this would result in chyluria, rather than frank lipiduria. It is also possible that urine extravasation occurred at the time of initial surgery, with consequential urine-induced lipolysis and subsequent migration of lipids either through the site of ureteric reimplantation, or through the bladder wall. We believe, however, that the most likely cause in our patient is that at the time of preparation of the ureter for reimplantation, a cuff of periureteric fat is likely to have been mobilised with the distal ureter and subsequently implanted within the bladder. Subsequent urine-induced lipolysis allowed the formation of the intravesical fat-fluid level, a feature rarely seen at cystoscopy.Presence of metallic hardware causes beam hardening artefact and resultant loss of tissue contrast at CT imaging, increasing the chance of missed pathology. Use of lung or bone window presets can help to minimise this risk, and is recommended as part of routine practice in the presence of metal prostheses or other such hardware.Fat within the urinary collecting system may be in the form of lipids, or in the form of a chylous emulsion, with distinct aetiologies for each.The presence of intravesical fat-fluid level on imaging may indicate the presence of unrecognised pathology, may be a sequelae of trauma, or secondary to intervention.Intravesical fat is an unusual finding at cystoscopy; lipiduria is a similarly uncommon CT finding, especially in the context of ureteric injury and reimplantation. Understanding the patient’s history is key to determining the likely aetiology of such findings.The combined urological ‘rendezvous’ procedure is a useful procedure employing both interventional radiology and cystoscopic techniques for the management of complex ureteric stricture or injury.


In September 2009, a 56-year old woman presented to our hospital with meningitis-like complaints. A CT scan demonstrated a small intracranial lesion in the posterior fossa. MRI, performed for further evaluation for this lesion, showed a broad dural-based implantation on the lower surface of the tentorium cerebelli, and a marked enhancement after administration of intravenous contrast  is a spindle-cell neoplasm of mesenchymal origin, that occurs in a variety of locations throughout the body most frequently the pleura. An intracranial location is rather rare. When present, they are often found along the dura or within the ventricles. They manifest around the 5SFT’s are iso- to hyperdense well-circumscribed lesions on CT imaging, sometimes with small calcifications. Smooth erosions of the adjacent skull can be seen, this in contrast to the hyperostosis which is often found in meningiomas. On MR imaging, SFT’s demonstrate heterogeneous signal intensity on T2 weighted imaging, with an heterogeneous contrast enhancement. Areas of low signal on T2 imaging that enhance avidly after administration of contrast are suggestive for SFT, this in contrast to meningiomas, which tend to show a more homogeneous enhancement after contrast administration. A dural tail can be present, though not always and is certainly not pathognomonic. Regions of restricted diffusion can be seen, representing hypercellular areas. The presence of flow voids is another feature that is often encountered. On MR spectroscopy raised lipid and lactate peaks are observed, which can be helpful in the differentiation with meningiomas that typically show elevated alanine and glutamate-glutamic acid peaks.As mentioned above, the main differential diagnosis is a meningioma, which should be on the number one position of everybody’s differential list when encountering a dural-based lesion. Next to the solitary fibrous tumor, other less common dural-based lesions are hemangiopericytoma, leiomyoma (or –sarcoma), lymphoma, sarcoid, and other very rare conditions.The authors declare that they have no competing interests.


Idiopathic sclerosing encapsulating peritonitis or abdominal cocoon syndrome (ACS) is a rare anatomical deformity characterized by the partial or complete encasement of the small intestine with fibrotic peritoneum. 193 cases have been described worldwide. The aim of this study is to present two cases of ACS successfully treated at the Surgical Clinic of the Agios Dimitrios General Hospital in Thessaloniki, Greece.  Two men (55 and 54 years old) presented to the emergency department complaining of abdominal pain, distension, constipation, nausea, and vomiting. Neither of these patients had any previous operations. The computed tomography scan of the first patient showed considerable distension of the small bowel, suggestive of internal herniation. The second case showed distention of the jejunum with no obvious cause. Both patients underwent emergency surgery. Intraoperatively, it was found that a fibrous membrane had completely covered the small intestine of the first patient and the jejunum and part of the large intestine of the second patient. Adhesiolysis and partial excision of the membrane were performed in both cases.  ACS is a rare cause of small bowel obstruction. Although conservative management with immunosuppressants and steroids has been described, surgical treatment is the gold standard.  Preoperative clinical suspicion of this disease can help determine the diagnosis and protect surgeons from intraoperative “surprises”. Idiopathic sclerosing encapsulating peritonitis is a rare cause of intestinal obstruction. It was first described in 1908 by Owtschinnikow and it was defined in 1978 by Foo et al. .The etiology of ACS remains largely unknown. However, secondary sclerosing encapsulating peritonitis due to previous abdominal surgery, peritonitis, tuberculosis, sarcoidosis, or peritoneal dialysis is more widespread. In a recent systematic review, the authors distinguished a third entity called peritoneal encapsulation . PeritonACS is classified into three types according to the extent of membrane encasement. In types I and II, the membrane encloses part or the entire small intestine, respectively. In type III, apart from the small intestine, other organs such as the stomach, colon, and liver are also enclosed .According to a recent systematic review, 193 cases of ACS have been reported worldwide, highlighting the rarity of this syndrome [Clinically, patients with this syndrome present themselves typically with small bowel obstruction. Nausea, vomiting, anorexia, abdominal pain, and a palpable abdominal mass may also exist in a subacute episode, whereas the acute form exhibits a more dramatic symptomatology . The cliWith regard to treatment, even though conservative management with immunosuppressants and steroids has been previously described, surgery is the gold standard . The opeThe aim of this article was to present two cases of ACS that were successfully treated at the Surgical Clinic of the Saint Dimitrios General Hospital in Thessaloniki, Greece. Both cases were concerning middle-aged males with no previous abdominal operations.A 55-year-old male presented to the emergency department with abdominal pain, abdominal distension, nausea, vomiting, and constipation persisting for two days. The patient stated that he had a history of chronic constipation that resolved spontaneously or with laxatives. He had no history of long-term medication, chronic systemic disease, or surgery.The physical examination revealed abdominal distension, tenderness, and absence of bowel sounds. The rest of the examination was unremarkable. His vital signs were within normal limits, and there was no clinical evidence of peritonitis.Abdominal X-rays showed multiple air fluid levels with dilated small bowel loops, suggestive of intestinal obstruction. CT images revealed internal herniation, which occupied part of the right abdomen, containing part of the ileum . The latth postoperative day.Intraoperatively, a fibrotic membrane covering all of the abdominal viscera was found. The small bowel loops were encased and interloop adhesions could be seen Figures  and 3. IA 54-year-old male presented to the emergency department of our hospital with acute cramping abdominal pain and nausea. He had similar episodes during the previous year, with milder symptoms which responded to conservative treatment, without the need for hospitalization. He had no significant past medical or surgical history.His clinical examination revealed a palpable mass in the right lower paraumbilical area, with sluggish bowel sounds. The radiographic findings were compatible with ileus. Due to the deterioration of his clinical status, a CT scan was performed, which revealed dilatation of the jejunal loops in the left upper abdomen, with fluid collection. Mesentery was thick-walled and amorphous calcifications were also seen . An explth postoperative day.Intraoperatively, a thick fibrotic membrane encasing the entire small intestine and part of the large intestine was found. Obstruction was due to the pressure applied by the thick membrane on the small bowel loops. During the operation, the fibrotic membrane was excised, followed by adhesiolysis between the intestinal loops . The hisACS is a rare syndrome that mainly affects the small bowel, leading to intestinal obstruction. Although it was initially considered to be more frequent in young girls living in tropical and subtropical regions , a systeThe idiopathic form of ACS is extremely rare, whereas the secondary form is more common . ClinicaAn early preoperative diagnosis and treatment of this syndrome are vital to preserve the circulation of the encased bowel segments and reduce the risk of strangulation . For thiIt is important for surgeons to be aware of ACS because the appropriate combination of clinical examination and imaging may facilitate the preoperative diagnosis.