Roentgenographic features of pulmonary disease caused by atypical mycobacteria

In a retrospective evaluation of chest roentgenograms and medical records of 40 patients with non-M tuberculosis (atypical) mycobacterial pulmonary disease, 34 had M avium-intracellulare, five had M kansasii, and one had M fortuitum. The roentgenologic spectrum of disease closely resembled that of M tuberculosis. One third of the patients had predisposing factors, and the disease predominated in middle-aged and elderly men. Two thirds of the patients had slow progression of the disease, with an average of 6.4 years before roentgenographic changes occurred. The diagnosis was frequently missed, and in most of the patients it was delayed from one to 16 years. Only after chronic, slow disease progression was atypical mycobacteriosis suspected clinically. The more widespread application of multiple simultaneous skin tests for atypical mycobacteria may improve the diagnosis and prognosis of this disease.