SMN1 and neoplasm with perivascular epithelioid cell differentiation: The tumor architecture frequently exhibits perivascular spindle cell proliferation in association with small-caliber vessels, while maintaining the absence of adipocytic components [5,8]. Immunohistochemical profiling demonstrates consistent strong positivity for melanocytic markers (HMB-45, Melan-A) and SMA, confirming dual myogenic and melanocytic differentiation, a diagnostic hallmark of PEComas [2].