Fibromuscular dysplasia causing atypical coarctation of the thoracic aorta: histological presentation of a case.

The authors report a case of atypical coarctation of the thoracic aorta discovered by chance in a 37-year-old man, victim of a car accident. The angiogram revealed a "string-of-beads" contour in the coarctate area while the left subclavian artery presented a severe stenosis at its origin. Vascular checkup examination failed to identify any additional vascular anomaly. The patient underwent surgical resection, with a Dacron prosthetic bypass. Histological study of the specimen removed, showed a typical perimedial and extensive medial types of fibromuscular dysplasia (FMD) of the aorta. Pathogenesis of this disease is discussed.