Subclavian artery aneurysm due to costoclavicular compression.

Proximal involvement of the innervation of the arm is a well recognised cause of hand symptoms; a proximal vascular abnormality is rarely responsible. This case report describes such a rare cause, namely, a post-stenotic aneurysm of the subclavian artery due to an abnormal first rib but in the absence of a cervical rib or scalene bands.