[Analysis of reasons for late recognition of tuberculosis and cancer of the lung and the ways of enhancing the efficiency of their differential diagnosis].

Difficulties in the differential diagnosis of tuberculosis and cancer of the lung were analyzed in 272 patients from a regional tuberculosis dispensary. The efficiency of using the real-time polymerase chain reaction (PCR) to detect Mycobacterium tuberculosis DNA molecule fragments in the sputum specimens from 111 patients of this category was studied to improve the differential diagnosis of these diseases. The real-time PCR was ascertained to be a rather highly sensitive (78.3%) and highly specific (96.1%) technique for tuberculosis diagnosis, which considerably improves the etiological recognition of the pathological process. Examinations of patients with peripheral lung cancer and benign round shadow formations in the lung yielded encouraging results. The specificity of the technique in this pathology is as high as 100%.