Malignant perivascular epithelioid tumor of the vagina: Report of a rare case with brief review of literature.

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors with immunohistochemical co-expression of melanocytic and myoid markers. Vaginal PEComas have been described in only nine cases so far. We describe the case of a 65-year-old female with a large growth in the left lateral vaginal wall. Biopsy imprint smears showed dispersed tumor cells with anisonucleosis, multinucleation, and bizarre forms, suggestive of a malignant tumor. Histopathology, however, showed perivascular arrangement of clear epithelioid cells, focal necrosis, intracellular brown pigment in few cells, and mitotic activity at 2 to 3 per 50 high power fields. Immunohistochemical positivity for vimentin, HMB-45, S-100 protein, desmin, and MyoD1 assisted in rendering a final pathological diagnosis of malignant PEComa of the vagina. Further work-up revealed metastatic deposits in liver and retroperitoneal lymph nodes. PEComa arising in vagina is an unusual phenomenon with the malignant variant being an extremely rare tumor. Awareness of the characteristic morphology and utilization of a panel of immunohistochemical stains are mandatory to be able to make a precise diagnosis and appropriate prognostication.