Abstract
Basilic vein aneurysms (BVAs) are extremely rare vascular entities, with fewer than 50 cases reported to date. They typically present as soft, compressible, and painless soft-tissue masses. We present a case of a 55-year-old man with a primary symptomatic BVA of the non-dominant forearm, complicated by previous sac thrombosis. Duplex ultrasonography confirmed a fusiform aneurysm measuring 18×15 mm with intraluminal thrombus and partial recanalization. Surgical excision under local anesthesia was performed successfully, without postoperative complications or disruption of the upper-extremity superficial venous outflow. The pathological report confirmed the diagnosis of a true degenerative venous aneurysm. A comprehensive literature review was conducted to summarize current knowledge on the pathogenesis, clinical features, differential diagnosis, imaging modalities, and treatment strategies of BVA.