[A case of cold abscess of the chest wall due to thoracic drainage for tuberculous pleuritis].

A 56-year-old man underwent thoracic drainage for two weeks for tuberculous pleuritis. He was put on antituberculosis chemotherapy with INH (400 mg), RFP (450 mg), and EB (750 mg). Two months later, he developed an elastic hard subcutaneous mass in the area of the previous thoracic drainage. The mass was 10 cm in diameter, warm, reddish and painful. Chest computed tomography (CT) revealed localized and encapsulated empyema in the left thoracic space and a subcutaneous abscess with rim enhancement in the left lateral chest wall. Magnetic resonance imaging (MRI) demonstrated a dumbbell abscess in the subcutaneous tissue communicating with the empyema through the chest wall. A needle aspiration of the subcutaneous abscess had acid-fast bacilli smears of 2+ and tested positive by polymerase chain reaction (PCR) for Mycobacterium tuberculosis. Thus, he was diagnosed with a cold abscess of the chest, with the empyema in the thoracic space draining into the chest wall through the cut for artificial drainage. Continuation of the anti-tuberculosis treatment and the drainage of the empyema with repeated aspiration reduced the subcutaneous mass, and the clinical and radiological course was favorable. Both the smear and culture for acid-fast test became negative. After completion of chemotherapy, there has been no disease recurrence.