Follicular thyroid adenoma with eggshell calcification presenting as an intensely hypermetabolic lesion on 18F-FDG PET/CT.

We report herein a case of follicular thyroid adenoma with an eggshell calcification presenting as an intensely hypermetabolic lesion on combined (18)F-fluorodeoxyglucose whole-body PET and CT ((18)F-FDG PET/CT) performed for staging work-up in a 68-year-old woman who had undergone distal gastrectomy with Billroth II anastomosis for early gastric carcinoma. The mass was intensely hypermetabolic (SUV(max) = 21.3 g/mL) on combined (18)F-FDG PET/CT, hypoechoic with an interrupted eggshell calcification on gray-scale ultrasonography (US), and showed intranodular vascularity on power Doppler US. Follicular adenoma should be considered in the differential diagnosis of a mass with an eggshell calcification on US and intense hypermetabolism on (18)F-FDG PET/CT. (c) 2009 Wiley Periodicals, Inc.