What Lies Beneath?

A 27 ~year~old woman with a history significant for mild intermittent asthma presented to the emergency department with complaints of progressive, increased dry cough and wheeze over 2 weeks, as well as slightly increased shortness of breath. She had no sputum or hemop~ tysis and no complaints of chest pain, night sweats, weight loss, or fatigue. The patient had not trav~ eled recently out of the New England area, had no recent contacts with ill persons, and did not use drugs, alcohol, or tobacco. Review of systems was otherwise unremarkable. On physical examination, the patient appeared anxious but was not acutely distressed. Her tern~ perature was 36.6°C (97.8°F) orally, heart rate 96 beats per minute, blood pressure 120/80 mm Hg, respiration 'rate 22/minute, and oxygen saturation 98% (by pulse oximetry) while breathing room air. The remainder of the physical examination was normal. Basic laboratory values were normal, apart from a lactate dehydrogenase level that was elevated fourfold. Chest film findings prompted a computed tomographic ( CT) scan of the patient's chest and a lung biopsy guided by thoracoscopy. continued