[A man with lung cancer and tuberculosis: a false positive by positron emission tomography and its clinical repercussions].

Positron emission tomography (PET) has come to play an increasingly important role in the evaluation of lung cancer patients, both for diagnostic staging and post-treatment follow-up. As is true for other techniques, PET gives false positive and negative results. False positives have been described in the presence of certain active infections and inflammatory lesions, such as tuberculous granulomas, coccidioidomycosis, aspergillosis and histoplasmosis. We report the case of a man whose PET gave a false positive and in whom both lung cancer and tuberculosis were present. A radical change in therapeutic approach was required, making the case interesting.