Incidental diagnosis of pulmonary tuberculosis in patients referred for diagnostic bronchoscopy or clinical follow-up due to malignant tumor disease: a cross-sectional study

Introduction: Incidental pulmonary tuberculosis is unexpectedly diagnosed in patients without prior clinical suspicion, usually during investigations of other diseases. Few studies have been conducted on this type of diagnosis. Here, we describe the general characteristics of incidental pulmonary tuberculosis diagnosis in patients undergoing bronchoscopy for neoplastic diseases. Materials and Methods: A cross-sectional study was conducted on patients with an incidental diagnosis of pulmonary tuberculosis identified during diagnostic bronchoscopy performed on individuals suspected of having cancer or undergoing cancer surveillance. tuberculosis diagnosis was diagnosed using GeneXpert MTB/RIF. Results: Eighteen patients were included, with a mean age of 50.3 years (SD: 20.4) and a predominance of females (55%;10/18). The most frequent comorbidities were diabetes mellitus (44%; 8/18) and systemic hypertension (44%;8/18). Seventeen% (3/18) of the patients had previously received oncological treatments. The most common symptom associated with the procedure indication was involuntary weight loss (61.1%, 11/18). Seventeen% (3/18) had a positive tuberculin test result, while none had a positive sputum smear result. Chest computed tomography revealed alveolar/interstitial infiltrates in 50% (9/18) of patients, masses in 28% (5/18), nodules in 22% (4/18), and lymphadenopathies in 28% (5/18). Discussion: Incidental pulmonary tuberculosis occurs in patients with suspected cancer or those under oncological follow-up. It is crucial to consider differential diagnosis in bronchoscopic studies.