[18F]FDG-PET/CT Demonstration of Young Adult Onset Stills Disease Mimicking Lymphoma.

Adult-onset Still's disease (AOSD) is an inflammatory disease of unknown aetiology, with no specific diagnostic tests. A 17-year-old female presented with fevers, night sweats and weight loss. Markedly FDG avid lymphadenopathy, and diffuse marrow and splenic uptake were demonstrated on [18F]FDG-PET/CT, most suggestive of lymphoma.