Hypermetabolic Hurthle Cell Adenoma on 18F-FDG PET/CT.

Thyroid incidentalomas are frequently reported on 18F-FDG PET/CT scan. High risk of malignancy is thought to be associated with increased metabolic activity and high standardized uptake value. Likewise, thyroid nodules with focal FDG avidity have a higher potential to be malignant. However, some benign nodules such as follicular and Hurthle cell adenomas can also present with focal hypermetabolic activity. We report a case of a 59-year-old lady diagnosed with gastric carcinoma, who had a hypermetabolic thyroid nodule on FDG PET/CT scan. Despite the complex texture of the nodule and intense focal avidity, the histopathology was consistent with Hurtle cell adenoma.