ABSTRACT
Perivascular epithelioid cell tumors (PEComas) are a rare, recently described group of mesenchymal tumors, which is composed of distinctive perivascular epithelioid cells. Primary cutaneous PEComas are composed of focally nested or trabecularly arranged groups of epithelioid cells with clear to eosinophilic cytoplasm and round to oval nuclei with obvious nucleoli. Here, we describe the case of a 27-year-old Korean man who was presented with a solitary, cutaneous nodule on his left popliteal fossa. Physical examination revealed a solitary, 1.2x1.0 cm-sized erythematous protruding nodule on his left popliteal fossa. Immunohistochemical evaluation showed that the epithelioid tumor cells were positive for HMB-45 and desmin. These clinical and histological findings were consistent with a diagnosis of primary cutaneous PEComa.