Contrast enhancement in tuberculous mediastinal/hilar lymphadenitis

Fourteen cases with tuberculous mediastinal/hilar lymphadenitis were studied. We described three enhanced types of lymphnodes images demonstrated by conventional computed tomography; type 1: homogeneous, type 2: multifocal low density, type 3: central low density and peripheral rim enhancement. Nine of 14 tuberculous lymphadenitis showed type 3 image. The biopsied lymphnode specimen which was classified as type 3 showed central necrosis surrounded by epithelioid cell granulomas and hyper-vascularities in the outer peripheral zone. In other diseases namely 7 sarcoidosis, 14 lung cancer and 6 lymphomas, rim enhancement was not found before treatment. Therefore it is concluded that the central low density and rim enhancement are frequently observed characteristic images in tuberculous mediastinal/hilar lymphadenitis. (author)