Intense F-18 FDG Uptake Noted in a Benign Bone Cyst

A 23-year woman was referred for fluorodeoxyglucose (FDG) positron emission tomography (PET) for restaging after excision of a Wilms tumor of the left kidney. Whole-body PET-CT scan revealed a focal area of intense FDG uptake in the right femoral head and neck region. Based on the CT findings, a well-defined cystic lesion with internal septation, the diagnosis of simple bone cyst was made. In conclusion, a benign bone cyst can cause a focal area of intense FDG uptake and therefore must be considered when FDG PET scans are evaluated in cancer staging.