Malignant perivascular epithelioid cell tumor

A malignant perivascular epithelioid cell tumor (PEComa) is an extremely rare, aggressive mesenchymal neoplasm characterized by distinctive perivascular epithelioid and spindle cells exhibiting dual melanocytic and myogenic differentiation Pathophysiologically, these tumors frequently harbor inactivating alterations in the *TSC1* or *TSC2* genes, or less commonly *TFE3* gene rearrangements, leading to constitutive hyperactivation of the mammalian target of rapamycin (mTOR) signaling pathway

A malignant perivascular epithelioid cell tumor (PEComa) is an extremely rare, aggressive mesenchymal neoplasm characterized by distinctive perivascular epithelioid and spindle cells exhibiting dual melanocytic and myogenic differentiation While these tumors can arise anywhere in the body, they occur predominantly in adults—with a notable female predilection—most frequently involving the uterus, retroperitoneum, gastrointestinal tract, and abdominopelvic soft tissues

While these tumors can arise anywhere in the body, they occur predominantly in adults—with a notable female predilection—most frequently involving the uterus, retroperitoneum, gastrointestinal tract, and abdominopelvic soft tissues Pathophysiologically, these tumors frequently harbor inactivating alterations in the *TSC1* or *TSC2* genes, or less commonly *TFE3* gene rearrangements, leading to constitutive hyperactivation of the mammalian target of rapamycin (mTOR) signaling pathway

While these tumors can arise anywhere in the body, they occur predominantly in adults—with a notable female predilection—most frequently involving the uterus, retroperitoneum, gastrointestinal tract, and abdominopelvic soft tissues Malignancy is distinguished pathologically by high-risk features such as large tumor size, high mitotic activity, necrosis, vascular invasion, and marked nuclear atypia

Pathophysiologically, these tumors frequently harbor inactivating alterations in the *TSC1* or *TSC2* genes, or less commonly *TFE3* gene rearrangements, leading to constitutive hyperactivation of the mammalian target of rapamycin (mTOR) signaling pathway