Hypermetabolic Hurthle Cell Adenoma on 18F FDG PET-CT scan

Thyroid incidentalomas are frequently discovered on 18F FDG PET-CT scan. A higher malignancy risk is thought to be associated with increasing metabolic activity and standardized uptake value (SUV). Likewise, thyroid nodules with focal FDG avidity have higher a malignant potential. However, some benign nodules like follicular and Hurthle cell adenomas can also present with focal hypermetabolic activity.
We report the case of a 59-year-old lady with gastric carcinoma, who was found to have an incidental hypermetabolic thyroid nodule on routine 18F FDG PET-CT scan. Despite the complex texture of the nodule and intense focal avidity, the histopathology was consistent with Hurtle cell adenoma.