[A case of infected bulla caused by Mycobacterium kansasii].

A 62-year-old man was referred to our hospital because of persistent sub-fever. A pulmonary fungal infection was suspected owing to the elevation of the serum-D-glucan level. Since a chest radiograph and a CT scan revealed intrabullous fluid in the right upper lobe, percutaneous needle aspiration was performed. Although acid-fast bacilli smears of the sputum and intrabullous fluid were negative, their cultures were found to be positive thereafter. M. kansasii was isolated and identified. After chemotherapy with antituberculous drugs, sub-fever improved and intrabullous fluid disappeared completely. Infected bulla caused by mycobacteria is very rare.