[Adventitial cystic disease of the popliteal artery: a clinical case].

Cystic adventitial degeneration is an uncommon vascular condition with a peculiar predilection for the popliteal artery. This disease most commonly affects young men and presents as rapidly progressive calf claudication. We report a case of a 80 years old man. The condition remains one of unknown etiology but our observation support that adventitial cysts are true ganglions which originate from adjacent joint capsule.