Expanding spectrum of pulmonary disease caused by nontuberculous mycobacteria

The clinical and radiographic features of 35 patients with nontuberculous mycobacterial (NTMB) pulmonary infections were reviewed. Radiographs of half the patients showed the pattern of cavitary upper-lobe infiltrates typical of reactivation tuberculosis; those of the other half had a radiographic pattern characterized by patchy, nodular infiltrates without an upper-lobe prevalence. Approximately half of the latter group showed multiple small cavities resembling those seen in bronchiectasis. These results suggest that studies in which the diagnosis of NTMB infection has been made primarily from sputum cultures may have been biased toward detecting cavitary disease. The spectrum of pulmonary disease caused by NTMB appears to be larger than previously appreciated. An enhanced awareness of alternate presentations of NTMB infections may result in earlier diagnosis.