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.

Primary Liver Perivascular Epithelioid Cell Tumor (PEComa): Case Report and Literature Review

“…Two or more criteria define the tumor as malignant. If only tumor size exceeds 5 cm or multinucleated giant cells are found, the malignant potential of the PEComa is considered as uncertain [ 3 , 26 ]. According to this assessment, our case fulfilled only one criterion of malignant PEComa: it had a partially infiltrative growth pattern.…”

“…Perivascular epithelioid cell tumors (PEComas) are a rare group of mesenchymal neoplasms composed of histologically and immunohistochemically distinctive perivascular epithelioid cells that were first proposed by Bonetti et al in 1992 [1,2]. This group includes angiomyolipoma, lymphangioleiomyomatosis, clear-cell "sugar" tumors, clear-cell myomelanocytic tumors of the falciform ligament or ligamentum teres, and other tumors that are classified as PEComa-NOS (not otherwise specified) [3]. They have a perivascular distribution and express both melanocytic and smooth muscle markers [4].…”