Thoracic outlet syndrome in a child--transaxillary resection of anomalous first rib.

Thoracic outlet syndrome (TOS) is extremely rare in children. Only several pediatric cases have been reported, and all presented with neurologic symptoms. The authors report on a 6-year-old boy with an asymptomatic left subclavian artery aneurysm caused by compression of the subclavian artery by an anomalous first rib with poststenotic aneurysmal dilatation.