An unusual etiology of a subclavian artery aneurysm.

A 22-year-old woman presented with a 3-month history of a pulsatile swelling in the right supraclavicular region. A CT angiogram revealed an aneurysm arising from the distal right subclavian artery. At surgery, the subclavian artery was almost entirely replaced by a well-vascularized tumor mass. The vascular tumor along with the native vessel was excised and replaced with a vascular prosthesis. Biopsy was suggestive of an epithelioid hemangioma (EH). In conclusion, an EH is a rare vascular tumor. The presence of vascular hyperplasia with plump endothelial cells protruding into the lumen is the most important discriminator in establishing the diagnosis of EH. Vascular neoplasms presenting as aneurysms should be considered, especially if other etiologies can be excluded.