Incidental Findings of Intense Radioiodine Uptake in Struma Ovarii and Bilateral Nonlactating Breasts Simultaneously on Postablation ¹³¹I SPECT/CT for Papillary Thyroid Cancer

A 52-year-old woman diagnosed with papillary thyroid carcinoma was referred for ¹³¹I therapy following total thyroidectomy. She was given 4,810 MBq (130 mCi) of ¹³¹I following 4 weeks of thyroid hormone withdrawal. A posttherapy scan showed intense, focal activity in the pelvis and intense, diffuse activity on both sides of the chest, which was localized to the right ovary and both breasts on SPECT/CT examination. She had bilateral nipple pain and a history of antidopaminergic drugs as combination medication for her rheumatoid arthritis and prokinetics during radioiodine therapy. On a ¹²³I whole-body scan 9 months later after stopping the drugs, bilateral breast uptake was not visible; however, right ovarian focal uptake was still visualized. Bilateral salpingo-oophorectomy was performed, and revealed struma ovarii with substantial internal necrosis due to radioiodine therapy. This case is interesting as two rare entities, ¹³¹I therapy-related struma ovarii and drug-related breast uptake, were simultaneously visualized.