Pathologic Findings of Surgically Resected Nontuberculous Mycobacterial Pulmonary Infection

Abstract

Background : Surgical resection of the involved lung for nontuberculous mycobacteria (NTM) has become an important curative therapy. However, there is limited information on the histopathological features of NTM pulmonary disease in Korean patients with NTM infection. Methods : We evaluated 51 specimens from 49 patients who were treated at our referral center from 2002 to 2009. Results : Almost all the cases showed bronchiectasis with lymphocytic infiltration. Variable features of granulomatous inflammation were found; well-defined granulomas in the parenchyma (68.6%), pneumonia-like granulomatous lesions (49.0%) and granulomatous inflammation in the bronchial wall (41.2%) were identified. The microscopic findings of cavitary lesions (37.3%) showed that these lesions were composed of granulomas and necrosis. Conclusions : The differentiation of tuberculosis from NTM could not be accurately made based solely on the histological features. However, the airway centered tendency of NTM reflected an airborn etiology, and this could be correlated with the classification according to the radiological findings. In addition, coexisting constitutional lung diseases, and especially bronchiectasis, were suspected to be predisposing conditions for NTM organisms to colonize and progress to true NTM pulmonary disease.