The role of transbronchial or thoracoscopic biopsy in the diagnosis of pulmonary MAC disease

Mycobacterium avium complex (MAC) pulmonary disease is increasing in incidence and becoming one of the major problems in respiratory medicine. We have surveyed the 65 cases of pulmonary MAC disease diagnosed from 1995 to 1999 in the northern central (Hokuriku) area of Japan. Among 30 patients who underwent biopsy, epitheroid granulomas were detected in 18. Three were male and 15 were female, with a median age of 67 years, ranging from 53 to 84 years. The method of biopsy was transbronchial in 15 cases and thoracoscopic in three. The species of pathogen were M. avium in 12 and M. intracellulare in six. Five patients were asymptomatic. The biopsy itself was sufficient to satisfy the bacteriological criteria of ATS statement in seven patients with positive tissue culture. The combination of the biopsy and the bronchoalveolar lavage established the diagnosis in an additional eight patients. Transbronchial or thoracoscopic biopsy has an important role in the diagnosis of pulmonary MAC disease.