A 56-year-old man with a 12 month history of productive cough, thorax pain related to respiration and around 10 kg unintended weight loss was referred to our department with a presumptive diagnosis of lung cancer. He smoked up to 60 cigarettes per dag and had estimated 100 pack/years. Routine laboratory investigations, including L and CRP revealed no abnormalities. He was diagnosed with COPD and lung function tests showed FEV1 over 2.2 l (59% of predicted value) and FVC over 3.7 l (79% of predicted value). He had a family history of lung cancer and had a history of alcohol overconsumption. Chest X-ray showed consolidation in the upper right lobe (Fig. 4) and the CT scan revealed an infiltrate with cavitations and irregular margins (Fig. 5). The patient underwent 18-FDG-PET and CT scan with the result of high metabolic activity of the lesion (Fig. 6). The next diagnostic step was bronchoscopy with brush and forceps biopsies with negative results concerning malignancy. We also sent bronchial wash samples to microbiological diagnostic with negative results concerning bacteria, fungi, legionella, mycoplasma, chlamidiae, negative direct microscopy and PCR for mycobacterium TB complex. Only cultivation of the bronchial wash provided the diagnosis by documented growth of the mycobacterium TB. The patient was started on standard anti-TB-therapy.