Abnormal Iodine-131 Uptake in a Benign Mucinous Ovarian Cystadenoma Mimicking Struma Ovarii

Abstract

A 37-year-old woman was referred for ablative radioiodine treatment 5 months after total thyroidectomy for pT1N1Mx papillary thyroid carcinoma. After thyroid hormone treatment withdrawal, serum thyroglobulin was 10.8 ng/mL. Posttherapeutic iodine-131 scintigraphy showed moderate cervical uptake compatible with remnant thyroid tissue and an intense right pelvic hot spot. Ultrasonography depicted a large 4-cm right ovarian cystic lesion. Struma ovarii was suspected. Laparoscopic right ovariectomy was performed and histologic examination found a benign mucinous cystadenoma of the ovary without any coexisting thyroid tissue.