SMN1 and neoplasm with perivascular epithelioid cell differentiation: According to WHO definition perivascular epithelioid cell tumor is a “mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells” [1].The PEComa cell does not have a known “normal” counterpart and this tumor is characterized by expression both melanocytic (such as HMB-45) and smooth muscle markers (such as SMA).