[Simultaneous detection of tumor cells and the positive result of genetic test for Mycobacterium tuberculosis in pleural effusion].

Pleural effusion is a frequently observed lesion in the course of respiratory diseases such as inflammatory process and cancer metastasis. Its cause may be either tuberculosis (the most common extrapulmonary location is the pleura) and malignant disease of the pleura. Confirmation of tuberculosis is often troublesome. The primary site of cancer may be also difficult to find despite the application of difficult diagnostic methods. Below we present history of 79-year-old female in whom carcinomatous cells and positive result of PCR for Mycobacterium tuberculosis in pleural fluid were discovered simultaneously suggesting the tuberculosis and cancer of unknown primary origin.