Abstract
Malignant struma ovarii (SO) is a rare tumor, and as a consequence, treatments and follow-up procedures are not clearly established. Presented in this study are two cases of suspicious ovarian masses, resected and corresponding to malignant SO on histopathology. Similar to thyroid cancer, we proposed complementary radioiodine therapy ((131)I) after total thyroidectomy (no malignancy was observed at this level in our two patients). Patients underwent treatment with 3.7 GBq (131)I followed by post-therapy whole-body scintigraphy, which can detect residual disease or occult metastases. Thyroid remnant ablation increases the sensitivity and specificity of follow-up testing using serum thyroglobulin levels as a tumor marker. Our two patients remained disease-free for 3 and 5 years, respectively, after treatment.