A 48-year-old man was referred with a 2 month history of chest tightness, intermittent non-productive cough and unintended weight loss of 3 kg in the past 2 month. He had no reported fever and had no prior medical history. He smoked around 30 cigarettes per day and had estimated 45 pack years.
Physical examination revealed no abnormalities. Routine laboratory investigations, including leukocytes (L) and C-reactive protein (CRP) presented normal values. The lung functions tests showed normal ventilation parameters with forced expiratory volume in 1 s (FEV1) of 3.5 l (94% of the predicted value) and forced vital capacity (FVC) of 4.5 l (97% of the predicted value). The chest X-ray presented an approximately 2 cm nodular infiltrate in the left lung (Fig. 1). Computed tomography (CT) scan of the chest confirmed infiltrate in segment 6 of the left lower lobe (Fig. 2). Under the presumptive diagnosis of malignancy we ordered a whole-body 18 flour-deoxyglucose positron emission tomography (18-FDG-PET) and CT scan. It revealed a high metabolic activity of the lesion (Fig. 3). With this imaging appearance, a provisional diagnosis of lung cancer was made. The patient underwent bronchoscopy with brush biopsies, endobronchial ultrasound transbronchial needle aspiration (EBUS -TBNA) and CT-guided lung biopsy with negative result concerning malignancy and without any diagnostically clarification. We still considered that the patient has lung cancer, so the next step was Video-assisted thoracoscopic surgery (VATS). The pathologic examination revealed no malignancy but instead caseous granulomatous inflammation. PCR for mycobacterium TB complex taken from the resected lung tissue was positive, so the diagnosis of pulmonary TB was confirmed, and the patient received standard anti-TB-therapy composed of pyrazinamide, isoniazid, ethambutol and rifampicin.
CT thorax showing infiltrate in the left upper lobe.