Clinicopathological characteristics of primary malignant cutaneous perivascular epithelioid cell tumor: case report and literature review.

Primary cutaneous malignant perivascular epithelioid cell tumors (PEComas) are extremely rare. Accurate diagnosis is critical for prognostic evaluation and guiding clinical management. Here, we report a case of a 19-year-old woman with a 1.1 cm exophytic red mass on her left upper limb. Histological examination revealed a dermal tumor composed of clear cells with prominent nucleoli. The tumor cells displayed cytologic atypia, nuclear pleomorphism, multinucleated giant cells, mitoses and invasive growth, with a multinodular distribution within the dermis and vascular invasion. Immunohistochemically, the tumor cells expressed cathepsin K, HMB45, and CD10. Based on morphological and immunohistochemical findings, we classified it as a primary malignant cutaneous PEComa. To date, only eight reported cases have been described as primary malignant cutaneous PEComas. The present case appears to be the youngest patient reported among all malignant PEComas.