A 34-year-old black female presents to your office with symptoms of cough, dyspnea, and lymphadenopathy. Physical exam shows cervical adenopathy and hepatomegaly. Her chest radiograph is shown below. How should you pursue diagnosis?

(c) Source: (Braunwald, 15/e, pp 1969-1974.) Sarcoidosis is a systemic illness of unknown etiology. Many patients have respiratory symptoms, including cough and dyspnea. Hilar and peripheral lymphadenopathy is 62 Medicine 10345 Berk_2p_03.k.qxd 5/15/03 10:23 AM Page 62 common, and 20 to 30% of patients have hepatomegaly. The chest x-ray shows symmetrical hilar lymphadenopathy. The diagnostic method of choice is transbronchial biopsy, which will show a mononuclear cell granulomatous inflammatory process. While liver and scalene node biopsies are often positive, noncaseating granulomas are so frequent in these sites that they are not considered acceptable for primary diagnosis. ACE levels are elevated in twothirds of patients, but false-positive values are common in other granulomatous disease processes.