Idiopathic true brachial artery aneurysm in a nine-month infant.

Upper extremity peripheral artery aneurysms are a rarely encountered arterial disorder. Brachial artery aneurysms seen in the pediatric age group are generally trauma resultant. A nine-month-old male infant patient presented with complaints of an asymptomatic mass in the arm. Following Doppler ultrasonography and magnetic resonance imaging (MRI) examinations, saccular aneurysm, originating from the left brachial artery was diagnosed in the patient without history of trauma. The aneurysm was resected by surgical intervention, and primary repair of the brachial artery was performed by end-to-end anastomosis. No complication was observed during the follow-up. Surgical intervention for upper extremity aneurysms should be initiated without delay in order to prevent extremity ischemia and amputation.