Mediastinal granulomatous lymphadenitis in a population at risk for HIV and tuberculosis

Background Granulomatous inflammation on transbronchial needle aspirates from mediastinal lymph nodes is an infrequent yet important finding. We determined associations between cytomorphological features and underlying aetiology in an area of high prevalence of HIV-infection and tuberculosis. Methods We identified cases with granulomatous inflammation on mediastinal aspirates from January 2003 to July 2010. Cytomorphological features were evaluated and graded according to a simple and reproducible system including the presence, quality (discrete or vague), and number (≤5 or more) of granulomas as well as the presence of necrosis, lymphocytes, multinucleated giant cells, and neutrophils. Results In 81 patients (36 male, 9 HIV-positive) the final diagnosis was tuberculosis in 37 (46%), sarcoidosis in 40 (49%), fibrosing mediastinitis in 1 (1%), and unknown in 3 (4%). The presence of necrosis (P