[Differential diagnosis of cavitary formations in the lungs of tuberculous and nontuberculous etiology].

In a group of 155 patients examined, 75 (48.2%) subjects were proved to have tuberculous cavities; 80 (51.8%), non-tuberculous cavities; 60, abscess and 20, cancer. From the roentgenologic point of view, unlike cavitary tuberculosis and abscess, trial therapy in case of a decomposing lung cancer is not successful in making the cavitation shrink. On the contrary, its dimensions get larger, it walls become significantly thicker and there appears a polycyclic recurrence of the inner configuration and horizontal shadow of the cavity content. The shadow progresses and gradually occupies the whole cavity. Roentgenologically, this process is known as the cavity filling symptom. Morphologic study of the resected material revealed that cancer growth from the cavity edges caused the thickening of the cancer cavity walls and its subsequent filling, which is well distinguished on the X-ray picture.