Primary Leiomyosarcoma of the Femoral Vein: a Case Report and Review of the Literature

Primary leiomyosarcoma of vascular origin is an exceptionally rare malignant tumor arising from the smooth muscle cells of the vessel wall. It represents less than 2% of all leiomyosarcomas and most commonly involves the inferior vena cava. Peripheral venous involvement, particularly of the femoral vein, is extremely uncommon and frequently mimics deep vein thrombosis, leading to diagnostic delay. We report the case of a 50-year-old woman with primary leiomyosarcoma of the left femoral vein initially misdiagnosed as deep vein thrombosis, who subsequently developed local recurrence and pulmonary metastatic progression. This case illustrates the diagnostic pitfalls, aggressive behavior, and therapeutic challenges associated with vascular leiomyosarcoma.