Abstract
Adenocarcinoma of the lung is the most common lung tumor, accounting for about 40% of the cases. Minimally invasive adenocarcinoma may be a part of a continuum of morphological changes, leading to the development of invasive adenocarcinoma of the lung. It is defined as a predominantly lepidic lesion measuring ≤3.0 cm with only small foci of invasion, the largest of which should be less than 0.5 cm. An association between lung cancer, Mycobacterium avium infection and Langerhans cell histiocytosis has already been described in past studies. We present a case of a 59-year-old patient with PET/CT data for metabolically active tumor (28 mm), which had increased in size and activity compared to the previous scan. On admission to our hospital, he had undergone 14 courses of chemotherapy at another institution for diffuse large B-cell lymphoma (DLBCL). After the left upper lobectomy, minimally invasive lung adenocarcinoma, Mycobacterium avium intracellulare and accompanying Langerhans cell histiocytosis were histologically verified.