Multifocal PEComa (PEComatosis) of the female genital tract and pelvis: a case report and review of the literature

Perivascular epithelioid cells (PECs) are constantly present in a group of tumors called PEComas, including angiomyolipoma (AML), clear-cell "sugar" tumor (CCST) of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear-cell myomelanocytic tumor of the falciform ligament/ligamentum teres and rare clear-cell tumors of other anatomic sites. PECs have distinctive morphologic, immunohistochemical, ultrastructural and genetic characteristics, including an epithelioid appearance with a clear to granular cytoplasm, a round to oval, centrally located nucleus, and an inconspicuous nucleolus. PECs also express melanocytic and myogenic markers like HMB45 and smooth muscle actin. PEComa is rare in human, and multifocal PEComas (PEComatosis) is extremely rare. Up to now there have been only less than 5 cases described in the literature. Here we report a 46-year old Chinese woman who had PEComatosis arising from the genital tract and pelvis. To our knowledge, this is the first case of PEComatosis ever reported in China.