Intense FDG uptake in a benign Hurthle cell adenoma

A 74-year-old man had an 8-mm pulmonary nodule detected as part of a chest computed tomography (CT) screening trial and was referred for positron emission tomography using 2-[F-18]-2-deoxy-D-glucose (FDG-PET). Imaging was performed on a PET/CT scanner (GE Medical Systems, Milwaukee, WI). Although the patient's pulmonary nodule was only minimally FDG-avid, there was a focus of intense FDG activity at the base of the neck anteriorly. PET/CT fusion images localized this uptake to the right lobe of the thyroid gland. Because of concern for an occult thyroid carcinoma, a thyroid ultrasound was performed, confirming a solid and vascular thyroid nodule. A fine-needle aspirate performed at the time of ultrasound revealed Hurthle cell neoplasm. Subsequent right thyroid lobectomy revealed a Hurthle cell adenoma.