A 21-year-old Chinese man presented with a nonproductive cough for the past 5 months. He denied fevers, chills, night sweats, chest pain, dyspnea, hemoptysis, or weight loss. He was an undergraduate with an unremarkable medical history. He denied any sick contacts and he never smoked. Laboratory tests showed a leukocyte count of 11,200/μL (normal range, 3,500-9,500/μL) with a high neutrophil count and a raised erythrocyte sedimentation rate of 81 mm/h. The purified protein derivative skin test result was positive, and a TB test (T.SPOT.TB; Oxford Immunotec) produced a positive result. The HIV test result was negative. The lung window of the patient's thoracic CT scan showed mottled, patchy opacification in the right lower lobe, and enlarged mediastinal and right hilar lymph nodes (Fig 1A). Bronchoscopy showed mucosal swelling and congestion (Fig 1B). A lymph node (station 11R) biopsy, obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) (Fig 1C), showed nonspecific necrosis. An acid-fast bacillus smear of bronchial secretion produced negative results. He was administered empiric anti-TB therapy (ethambutol, isoniazid, pyrazinamide, and rifapentine). But his cough had not improved by 4 months later. Thus he came to our hospital for a second opinion.