Rectal Perivascular Epithelioid Cell Tumor with Partial CD117 Expression and Giant Cells

Abstract

Perivascular epithelioid cell tumor (PEComa) is a rare entity, characterized as a mesenchymal tumor with coexpression of melanocytic and smooth muscle markers. The involvement of the gastrointestinal tract is described in up to 100 cases in the English literature. Rectal PEComas are even more uncommon, with only 10 previously described cases. We present the case of a 62-year-old man with rectal PEComa with some unusual features, such as gastrointestinal stromal tumor-like CD117 positivity and HMB45 (human melanoma black-45)-positive multinucleated giant tumor cells. After 12 months' follow-up, the patient is alive with no radiologic, endoscopic, or histologic evidence of disease recurrence.