Pulmonary Takayasu's arteritis masquerading as acute pulmonary embolism.

Pulmonary involvement may sometimes be the initial presentation of Takayasu's arteritis (TA). Since the signs and symptoms of pulmonary TA may be subtle and may not be easily distinguishable from other pulmonary diseases, one has to maintain a high index of suspicion. Cases of pulmonary TA mimicking chronic thromboembolism have been reported. We describe a patient with TA whose initial presentation mimicked acute pulmonary embolism. The patient presented with a 3-day history of cough and shortness of breath and had multiple bilateral perfusion defects on ventilation-perfusion scan, typical of acute pulmonary embolism. However, the constellation of clinical features, elevated erythrocyte sedimentation rate and the angiographic appearance helped us establish the correct diagnosis of pulmonary Takayasu's arteritis. At a 6-year follow-up, the patient had no worsening of pulmonary symptoms but presented with postural dizziness with angiographic evidence of carotid and innominate artery stenosis; she underwent arterial bypass grafting. In young women presenting with a clinical picture of acute pulmonary embolism without the previous history (or risk factors) of thromboembolism, pulmonary TA must be considered in the differential diagnosis.