[A case of pulmonary Mycobacterium intracellulare infectious disease with a solitary pulmonary nodule in the peripheral lung field].

A 63-year-old woman was admitted to our hospital because of a solitary nodule (20 x 20 mm) in the right S3 which was first detected during a health examination. Because radiological findings for the nodule, such as pleural indentation and spicula on chest CT led us to suspect a pulmonary adenocarcinoma, we could not completely rule out lung cancer and performed a bronchoscopic examination on the third day after admission. However, no definite diagnosis could be made. Therefore, video-assisted thoracic surgery (VATS) was performed, and a caseating epitheloid granuloma with acid-fast bacilli was found. Initially, we administered antituberculous drugs for pulmonary tuberculoma, but then changed to combined chemotherapy using RFP, EB, CAM and SM after identification of Mycobacterium intracellulare by a culture test of resected tissue. We report a rare case with a solitary nodule caused by pulmonary Mycobacterium intracellulare infectious disease which is indicative of lung cancer.