Purpose. Using the example of a clinical case to show the difficulty of differential diagnosis of lung tumors and tuberculosis, especially in coexistence.

Materials and methods. The clinical observation of a combination of tuberculosis and typical carcinoid of lower lobe of left lung at the same locus is given.

Results. The current clinical observation clearly demonstrates the difficulties of diagnostics of tuberculosis and lung cancer in coexistence, also a demand of additional diagnostic actions for a valid verification of diagnosis in the current clinical case is shown.

Conclusion. Combination of tuberculosis and lung cancer remains an up-to-date controversial issue in medical community. Difficulties in diagnosing due to the possibility of these diseases’ manifestation in poor symptoms and similarity of the x-ray patterns, as well as changes in the concepts of coexistence and mutual influence of these pathologies encourage interest in finding and choosing new optimal and effective diagnostic methods.