Prostatic perivascular epithelioid cell tumor: A rare entity and literature review

Abstract

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm comprising perivascular epithelioid cells that express myomelanocytic immunophenotype, while stain negative for epithelial markers. We describe a case of prostatic PEComa in a 55-year-old man, who had one month history of frequent urination, hesitancy, and sensation of incomplete voiding. Radiological imaging disclosed prostatomegaly. Despite the medical treatment offered, episodes of urinary retention persisted. Subsequently, he underwent endoscopic transurethral resection of the prostate, histology showed tumor arranged in nests surrounded by thin delicate vessels. The tumor cells were epithelioid with abundant clear-to-eosinophilic cytoplasm, round nuclei, and inconspicuous nucleoli. Bizarre multinucleated giant cells, conspicuous mitosis and focal necrosis were evident. On immunohistochemistry, the tumor cells were diffusely positive for Human Melanoma Black (HMB45) and smooth muscle actin, negative for anti-cytokeratin monoclonal antibodies (AE1/AE3), Homeobox protein (NKX3.1), GATA Binding Protein 3 (GATA3), synaptophysin, Transcription Factor Binding to Immunoglobulin Heavy Constant Mu (IGHM) Enhancer 3 (TFE3), desmin, and SRY (sex determining region Y) -Box Transcription Factor 10 (SOX10). This uncommon case illustrates our diagnostic ordeal with a brief discussion on its nosology and a comprehensive literature review.