Solitary Pulmonary Nodule

Occasionally, MAC disease may present as a solitary pulmonary nodule, which may have the spiculated appearance typical of malignancy [1].

This spiculated, solitary pulmonary nodule was resected because of suspected cancer. Histologically, it was a granuloma, and the culture yielded MAC.

Solitary pulmonary nodules, 1 to 5 cm in diameter, may be found without lobar preference [1]. Sometimes they occur as multiple nodules in clusters [2]. Solitary nodules, suspected of being cancer, were found in 16 (10 women) patients (median age 65, range 32-77) with MAC disease who underwent open lung biopsy for diagnosis. Necrotizing granulomas were present in 7, and non-necrotizing granulomas in 9. Cavitation was absent [3]. Smaller nodules detected only on CT may be more prevalent than thought, and may correspond to the peripheral portion of the Ghon complex seen in tuberculosis [2].


1. Levin D. Radiology of pulmonary Mycobacterium avium-intracellulare complex. Clin Chest Med 2002; 23:603-612.

2. Miller W Jr. Spectrum of pulmonary nontuberculous mycobacterial infection. Radiology 1994; 191:343-350. Abstract

3. Marchevsky A, Damsker B, Gribetz A, Tepper S, Geller S. The spectrum of pathology of nontuberculous mycobacterial infections in open-lung biopsy specimens. Am J Clin Pathol 1982: 78:695-700. Abstract

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