scenerios of tuberculosis with answers
Tuberculosis Scenario Questions & Answers 1. Secondary TB with Apical Cavitary Lesions Question: A 55-year-old man with a history of smoking presents with a 3-month history of chronic cough, night sweats, weight loss, and occasional blood-streaked sputum. Chest X-ray shows cavitary lesions in the upper lobes of the lungs. Sputum smear is positive for acid-fast bacilli (AFB). 👉 What is the likely diagnosis, and why are the lesions located in the upper lobes? Answer: The patient most likely has secondary (reactivation) tuberculosis . Secondary TB occurs due to reactivation of dormant Mycobacterium tuberculosis bacilli in a previously infected individual, often when immunity is weakened. The lesions are typically located in the upper lobes because these areas have higher oxygen tension , which favors the aerobic growth of M. tuberculosis . Cavitary lesions result from caseous necrosis and tissue destruction, allowing the bacilli to multiply and be expectorated, making the p...