[Fibrosing mediastinitis: a rare cause of fever].

A 47-year-old woman was examined due to fever of unknown origin. She had been on holiday in Southeast Asia. Routine laboratory investigations confirmed the presence of inflammation. Serology for Hepatitis B virus, HIV, Borrelia, Cytomegalovirus, toxoplasmosis, lues, Epstein Barr virus, brucellosis, bartonellosis, histoplasmosis and auto-immune factors was negative. CT-scans of the chest and abdomen failed to reveal the cause. Finally, gallium-67 scintigraphy showed an increased uptake in the left mediastinum and the left side of the neck. This led to the discovery of an infraclavicular mass. On histological examination of the surgical excision biopsy the diagnosis 'fibrosing mediastinitis' was made. The patient was treated successfully with corticosteroids.