[Coexistence of lung cancer and active pulmonary mycobacteriosis]

The aim of this study is to clarify the clinical and pathological anatomical picture of cases in which lung cancer and active pulmonary mycobacteriosis are intermingled in the same lobe of the lung.

We analyzed clinicopathological data on 11 cases in which lung cancer and active pulmonary mycobacteriosis are intermingled in the same lung lobe out of 61 admitted cases of coexisting lung cancer and active pulmonary mycobacteriosis, encountered at National Hospital Organization Tokyo National Hospital during the period from 1991 to 2003.

The subjects were 10 men and 1 woman, with a mean age of 68 years. The species of mycobacteriosis were M. tuberculosis in 6 and nontuberculous mycobacteriosis in 5 (M. avium disease and M. abscessus disease in 2 each, and M. kansasii disease in 1). The frequency of the mixture was 13% (6/45) in patients with lung cancer and tuberculosis and was 31% (5/16) in patients with lung cancer and nontuberculous mycobacteriosis. Radiographic findings revealed that both cancer shadows and mycobacteriosis shadows are identified in 8 of the 11 patients, whereas cancer shadows were recognized but mycobacteriosis shadows could not be pointed out in the remaining 3 patients. We divided 7 cases (5 resection scases and 2 autopsy cases) with the mixture of cancer and mycobacteriosis into 2 types from the macroscopic images: (1) type A (4 cases, the foci of lung cancer and tuberculosis, which were separated originally, progressed mutually, and has adjoined), and (2) type B (2 cases, the foci of mycobacteriosis existed within or in the edge of the foci of lung cancer). There were 3 nontuberculous mycobacteriosis cases and 1 tuberculosis case in type A, and 2 tuberculosis cases and 1 nontuberculous mycobacteriosis in type B. In nontuberculous mycobacteriosis cases, cancer and mycobacteriosis had often adjoined under the conditions of preexisting lung disease, such as a lung cyst, whereas in tuberculosis cases, it was characteristically shown that the wall of encapsulated caseous nodules was destroyed by cancer invasion, and that the tuberculous nodules were reactivated. These findings seemed to be related to exogenous infection of nontuberculous mycobacteriosis to the injured lungs and to endogenous reactivation of tuberculosis from inactive tuberculous lesions.

Lung cancer and active pulmonary mycobacteriosis are often seen intermingled in the same lung lobe, and the mixture pictures of the two diseases are variable. The physicians should carefully note about the mixture of lung cancer and mycobacteriosis, though the findings are not clear on the chest plain radiographs.