Thelansis

Perivascular epithelioid cell tumors (PEComa) are a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. These tumors include renal angiomyolipoma, lymphangioleiomyomatosis; clear cell sugar tumor of the lung; and similar tumors occurring in the retroperitoneum, kidney, uterus, pancreas, and a variety of other visceral and soft-tissue sites. PEComas of the kidney include various histologic subtypes of angiomyolipomas such as the classic angiomyolipoma, epithelioid angiomyolipoma, oncocytomalike angiomyolipoma, and lymphangiomyomatosis of the renal sinus. PEComas are related to the tuberous sclerosis complex (TSC) and have the characteristic genetic alterations of TSC, including the deletions of the short arm of chromosome 16p (TSC2 gene). Their perivascular location histologically characterizes PEComas, usually epithelioid or occasionally spindle cell morphology, and coexpression of human melanoma black (HMB)...