Tuberculosis

This is a chest x-ray of a young HIV-negative African man who presented with a cough and fever. There is patchy shadowing, cavitation and mild collapse of the right upper lobe (note the raised horizontal fissure), but no hilar enlargement. A sputum sample was positive for acid-fast bacilli (AFBs) and culture demonstrated Mycobacterium tuberculosis. These radiological features are typical of post-primary pulmonary tuberculosis. Post-primary disease is characteristically patchy, involves the upper zones and is associated with cavitation and fibrosis. Hilar lymph node enlargement is not a feature. In contrast, primary tuberculosis shows unilateral or bilateral hilar lymph node enlargement in association with a Ghon focus. In the early stages of HIV infection, pulmonary tuberculosis may present following the pattern of typical post-primary disease, such as in this case. Also, primary disease is relatively common, and there may be a mixture of both primary and post-primary radiological features.