Intravascular Lipoma.

Intravascular lipomas are rare benign tumors composed of adipose tissue that originate from the walls of blood vessels. They most commonly arise from veins, are typically asymptomatic, and rarely occur in the lower extremities. When large, these tumors can cause symptoms related to venous obstruction, such as swelling and pain. We report a case of a 75-year-old man with an intravascular lipoma in the right common femoral vein, identified during evaluation of lower extremity swelling and poorly healing ulcers. Surgical resection was ultimately required. This case contributes to the few published reports of pathologically proven symptomatic intravascular lipomas involving the lower extremity veins. Comprehensive preoperative imaging played a critical role in characterizing the lesion. The case facilitates a discussion of key differential diagnoses, such as atypical lipomatous tumors/well-differentiated liposarcoma and leiomyosarcoma. · Intravascular lipomas are rare and generally asymptomatic masses that most often arise in the veins of the upper extremity and thorax.. · The differential diagnosis for a fatty intravascular mass includes benign lipoma, atypical lipomatous tumor (ALT)/well-differentiated liposarcoma, and leiomyosarcoma.. · Benign lipomas usually demonstrate homogeneous fat signal with thin fibrous septa and minimal nonadipose components.. · Imaging features suggestive of ALT/well-differentiated liposarcoma are reduced and/or heterogeneous fat composition, thickened septa, and nodular nonadipose tissue..