Chest radiographs revealed a consolidation-like shadow in the left lower lung field with an obliteration of the silhouette of the left diaphragm (Fig 1
). A chest CT scan demonstrated a nodular opacity with cavity formation and a small amount of pleural effusion in the left hemithorax (Fig 2
). Diagnostic thoracentesis obtained a bloody and exudative fluid with an adenosine deaminase level of 20.7 U/L, a lactic acid dehydrogenase (LDH) level of 1,043 U/L (serum LDH level at that time, 214 U/L), and a leukocyte count of 51,200 cells/μL, in which the differential cell count of lymphocytes was > 90%. Several examinations of the pleural fluid cytology were negative for malignancy. Although bacteriologic smears and a polymerase chain reaction of the pleural fluid were negative for tuberculosis, the attending physician started a course of empiric chemotherapy with antituberculous agents because of the cavitary lesion found on the initial CT scan (Fig 2), a positive tuberculin skin test result, and the age of the patient. However, the symptoms and pleural effusion did not respond to medication. The patient was referred to our surgical department for treatment of a complicated left pneumothorax approximately 2 months after receiving the medication.