Clear cell "sugar" tumor of the lung: a well-enhanced mass with an early washout pattern on dynamic contrast-enhanced computed tomography. (1/32)

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Perivascular epithelioid cell tumor (PEComa) of abdominal cavity from falciform ligament: a case report. (2/32)

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Malignant perivascular epithelioid cell tumour of the round ligament mimics leiomyoma on computed tomography. (3/32)

We report a case of a 45-year-old woman who had a palpable mass in the left lower quadrant of the abdomen. Computed tomography (CT) showed a circumscribed mass in the left round ligament of the uterus. The mass had heterogeneous density and enhancement accompanied by mottled calcification, which was initially identified as a leiomyoma. A histopathological examination revealed a malignant perivascular epithelioid cell tumour (PEComa), which is a rare soft tissue tumour. This case demonstrates that the appearance of malignant PEComa on the CT can mimic leiomyoma, which is the most common tumour of the round ligament. To the best of our knowledge, this is the first report of a CT appearance of this round ligament tumour. The radiological features and differential diagnosis are discussed.  (+info)

Pancreatic PEComa (sugar tumor): MDCT and EUS features. (4/32)

CONTEXT: PEComas (tumors showing perivascular epithelioid cell differentiation) of the pancreas are exceedingly rare. CASE REPORT: We herein report on a 60-year-old female who noticed a bulge in her right upper quadrant while exercising. Subsequent multidetector-row CT scan showed a 3.5 cm well-defined, encapsulated, hypovascular, solid tumor in the body of the pancreas. Endoscopic ultrasound demonstrated a mixed hypo- and hyper-echoic, well-defined, heterogeneous tumor. CONCLUSIONS: Although three pancreatic PEComas (sugar tumors) have been described previously, to the best of our knowledge, this is the first report of a pancreatic PEComa with illustration of its multidetector-row CT and endoscopic ultrasound features in the radiological literature.  (+info)

Perivascular epithelioid cell tumor (PEComa) of the liver diagnosed by contrast-enhanced ultrasonography. (5/32)

Perivascular epithelioid cell (PEC) is a unique cell which expresses both myogenic and melanocytic markers, and forms PEComa. A 36-year-old woman presented with a 35 mm-diameter liver tumor. MRI showed poor fat component in the tumor. Contrast-enhanced ultrasonography using the newly developed enhancing reagent, Sonazoid, clearly demonstrated early-phase enhancement of the tumor and rapid drainage of the reagent to veins, suggesting a PEComa. Lateral segmentectomy of the liver was performed. Histologically, epithelioid tumor cells around the vessels were immunostained with both HMB-45 and alpha-smooth muscle actin, confirming the diagnosis of PEComa. No recurrence has been found for 18 months following the operation.  (+info)

Clinical activity of mTOR inhibition with sirolimus in malignant perivascular epithelioid cell tumors: targeting the pathogenic activation of mTORC1 in tumors. (6/32)

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A perivascular epithelioid cell tumor of the stomach: an unsuspected diagnosis. (7/32)

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasia and currently well recognized as a distinct entity with characteristic morphological, immunohistochemical and molecular findings. We report a case of PEComa arising in the antrum of a 71-year-old female with melena. The tumor, located predominantly in the submucosa as a well delimited nodule, measured 3.0 cm in diameter and was completely resected, with no evidence of the disease elsewhere. Histologically, it was composed predominantly of eosinophilic epithelioid cells arranged in small nests commonly related to variably sized vessels, with abundant extracellular material, moderate nuclear variation and discrete mitotic activity. No necrosis, angiolymphatic invasion or perineural infiltration was seen. Tumor cells were uniformly positive for vimentin, smooth muscle actin, desmin and melan A. Although unusual, PEComa should be considered in the differential diagnosis of gastric neoplasia with characteristic epithelioid and oncocytic features and prominent vasculature.  (+info)

Perivascular epithelioid cell tumor (PEComa) of the uterus with aggressive behavior at presentation. (8/32)

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells (PECs). Both benign and malignant tumors have been identified, but the criteria for diagnosis of malignancy have not been fully established due to the rarity of the tumor. We report on a case of uterine PEComa in a 33-year old woman with lymph node metastasis at presentation. The tumor had the characteristic histologic features of PEComa with cytologic atypia, mitotic activity of 2/10 high power field (HPF), and necrosis; it exhibited immunopositivity for HMB-45, calponin and desmin and was negative for melan-A. The patient received neoadjuvant chemotherapy, debulking surgery and adjuvant chemotherapy. No evidence of recurrence or metastasis was apparent 8 months after surgery.  (+info)