Serendipitous detection of Cushing's disease by FDG positron emission tomography and a review of the literature

A 70-year-old woman was referred for F-18 fluorodeoxyglucose (FDG) positron emission tomographic (PET) imaging of the brain to evaluate progressive dementia and neuropsychiatric symptoms. Although she had a history of hypertension and diabetes mellitus, she did not exhibit phenotypic features of Cushing's disease. The FDG-PET images revealed marked FDG uptake in the pituitary gland but no evidence of degenerative dementia. Two macroadenomas were confirmed by magnetic resonance imaging. Endocrinologic evaluation revealed Cushing's disease. After surgical resection of the tumors, the patient's symptoms decreased markedly.