Takayasu's arteritis.

Takayasu's arteritis, an inflammatory and obliterative disease of medium and large arteries, is classified as a giant cell arteritis. It has a predilection for the aortic arch and its branches and the pulmonary arteries. Unlike atherosclerotic vascular diseases, Takayasu's arteritis affects young women primarily. Early symptoms may be mainly systemic and may resemble polymyalgia rheumatica. The etiology is unknown, but infectious agents and autoimmunity have been suggested to play a role. Diagnosis is based on symptoms, physical findings, and angiographic findings, because tissue diagnosis rarely is feasible. The two cases reported here represent contrasting phases of Takayasu's arteritis.