[Cystic degeneration of adventitia]

A description is presented of the cystic degeneration of the adventitia of the external iliac and femoral arteries. Numerous cysts in the adventitia compressed the arterial lumen and resulted in thrombotic occlusion. The histologic picture was similar to that of tendinous sheath ganglion. A list is given of cases already described with a discussion of the views concerning its aetiology and pathogenesis.