Imaging of Giant Cell Arteritis: Evidence of Splenic Involvement Using FDG Positron Emission Tomography

A 63-year-old man with fever of unknown origin was referred for F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). Intensive clinical workup, including computed tomography of the brain, thorax, and abdomen and leukocyte scintigraphy revealed no abnormalities. F-18 FDG PET showed increased FDG uptake in the major thoracic vessels and abnormal splenic FDG accumulation. Temporal artery biopsy confirmed the diagnosis of giant cell arteritis. A follow-up FDG PET scan after 6 weeks of prednisolone treatment showed a marked reduction of the vasculatory and splenic uptake. This case report suggests splenic involvement in giant cell arteritis.