[Case of pulmonary mycobacterium avium complex disease, showing hypersensitivity pneumonitis-like diffuse shadow].

A 59-year-old man who had just completed therapy for tuberculosis, fell down in sauna and was admitted to a hospital. As acid-fast bacilli were positive (Gaffky 2) in sputum and residual cavity was shown in the right upper lobe on chest X-ray, he was transferred to our hospital. In spite of starting antituberculous chemotherapy, small nodular shadows appeared diffusely and were changed into ground-glass appearance on chest X-ray. The trans-bronchial-lung-biopsy revealed alveolitis mainly composed of lymphocyte infiltration with non-caseous epithelioid cell granulomas and organization which are likely to appear in hypersensitivity pneumonitis. As the acid-fast bacilli were identified as Mycobacterium avium, clarithromycin and kanamycin were added to the chemotherapy, but no improvement was observed in clinical feature. Corticosteroid therapy was further added and clinical feature improved immediately. Although we did not examine the presence of Mycobacterium avium in the water of sauna bath, we suspected this case as Hot Tub Lung based on clinical features and the response to treatment.