Clinical significance of ¹⁸F-fluoro-dexoxyglucose positron emission tomography in patients with adult-onset Still's disease: report of two cases and review of literatures.

Adult-onset Still's disease (AOSD) is a multi-systemic inflammatory disease that usually presents with high fever and variable systemic features. The pathogenesis and etiology of AOSD have not yet been clearly determined. In addition, there is no diagnostic test for AOSD. Even though some useful diagnostic criteria or laboratory findings, such as serum ferritin levels, have been proposed, useful imaging studies for the diagnosis or follow-up of AOSD have not been developed. We performed (18)F-fluoro-dexoxyglucose positron emission tomography ((18)F-FDG PET) on two AOSD patients who presented with a fever of unknown origin. In these patients, we initially identified abnormally increased FDG uptake in multiple lymph nodes, the spleen, or bone marrow. We then identified significantly decreased uptake during a follow-up study. On the basis of these cases, we suggest that (18)F-FDG PET may have the potential in the diagnosis of AOSD, as well as monitor clinical changes in the disease. More further investigation of (18)F-FDG PET in AOSD is needed in larger population.