[A case of pulmonary Mycobacterium scrofulaceum infection and review of the tendency towards recent acid-fast bacilli infection].

A 47-year-old man presented to a local physician with a chief complaint of sputum and cough for 3 months. Chest X-ray showed bilateral consolidation in the upper lung fields, and the patient was suspected to have pulmonary tuberculosis: he was then referred to our hospital. Smear and culture of both sputum and gastric juice showed acid-fast bacilli, and we started administration of rifampicin, isoniazid, ethambutol, and pyrazinamide. Results of the culture and identification test showed the causative bacillus to be Mycobacterium scrofulaceum (M. scrofulaceum). We stopped pyrazinamide and added clarithromycin to the treatment regimen, which resulted in symptomatic relief and radiological improvement. The frequency of pulmonary nontuberculous mycobacteriosis is increasing: in contrast, pulmonary infection by M. scrofulaceum has been decreasing. Nevertheless, M. scrofulaceum infection should be considered in the differential diagnosis from tuberculosis when the results of radiological findings and sputum culture suggest pulmonary tuberculosis.