TISSUE AND CELLULAR REACTIONS IN THE LUNGS CAUSED BY DIFFERENT STRAINS OF SLOWLY GROWING NONTUBERCULOUS MYCOBACTERIA
Aim: to describe tissue and cellular reactions in pulmonary nontuberculous mycobacterioses caused by different strains of nontuberculous mycobacteria (NTM) in resection samples from patients with pulmonary tuberculomas. Materials and methods. We conducted morphological, microbiological and molecular genetic studies of resection samples from 40 patients with diagnosed pulmonary tuberculoma, which were also infected with different strains of slowly growing NTM, and 38 pulmonary tuberculoma patients without concomitant mycobacteriosis (controls). Results. The development of nontuberculous mycobacteriosis is accompanied by severe non-tuberculous lymphoid infiltration of the pulmonary parenchyma, formation of histiocytic and histiocytic macrophage granulomas without caseous necrosis, which is especially typical for M. avium (22.5%), M. intracellulare (7.5%). Histiocytic granulomas are exposed to rapid fibrosing, which results in impaired structural homeostasis of the respiratory tract and developing pneumosclerosis, especially in the perivascular zone. Typical presentations of infections caused by M. kansasii (30%) and M. xenopi (27.5%) are lymphoid histiocytic infiltration of the walls of terminal respiratory ways and adjacent lung tissue accompanied by fibrosing, narrowing of the lumen or developing bronchoalveolar ectasia in the form of thin-wall cavities with ciliated epithelium. The obtained data can be used for differential diagnosis of pulmonary TB and pulmonary nontuberculous mycobacterioses.