An elderly woman with fever and hilar adenopathy.

A 71-year-old white female with a history of chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, and right total knee and hip replacement was admitted with right lower extremity cellulitis. A right lower extremity Doppler examination was negative. Administration of cefazolin produced improvement of the cellulitis. The patient complained of shortness of breath and a nonproductive cough. She was evaluated by a pulmonologist for intermittent hypoxia despite a clear chest radiograph. A ventilation-perfusion scan was negative, and the shortness of breath, hypoxia, and cough were attributed to COPD. Chest computed tomography (CT) demonstrated emphysematous changes, atelectasis at the lung bases, and mediastinal and hilar lymphadenopathy. The patient also admitted to having fevers up to 38.9”C intermittently for 3 months. She had been maintained on approximately 10 mg of prednisone for at least 6 months and had travelled to Arizona, Califorma, Chicago, and Spain. She had no pets nor any known tuberculosis contacts. The patient’s physical examination was notable for a temperature of 38.3”C and a respiratory rate of 24 breaths per minute. Her lungs showed rhonchi bilaterally, her right lower extremity was mildly erythematous and warm, with no cords. Laboratory studies were remarkable for a white blood cell count (YVEK) of 3.7 X 103/mm3, lactate dehydrogenase (LDH) 1062 units/ml, aspartate transaminase (AST) 47 units/ml, arterial blood gases (ABG) on room air: pH 7.5 1, HCO, 19 meq/L, CO, 14.7 mm Hg, PO, 84 mm Hg, 0, saturation 97%. A gallium scan was obtained, which showed increased uptake of the right paratracheal, bilateral hilar and carinal lymph nodes. A thoracotomy was performed for a biopsy of a mediastinal lymph node. The biopsy