Functional Imaging in 2 Rare Cases of Struma Ovarii With Contrasting Features

We present 2 cases, one with benign struma ovarii that was diagnosed preoperatively on Tc- 99 m and I-131 scans and another of malignant struma ovarii with peritoneal metastases that were detected postoperatively on 18 F-FDG PET/CT and post-radioiodine (I-131) therapy scans. Benign struma ovarri had a rare occurrence of coexisting Graves' disease, while malignant struma ovarii demonstrated rare peritoneal involvement on functional imaging. Even though rare, struma ovarii can present with contrasting features and may require extensive workup, including functional scans and radioiodine therapy as shown in these cases.