Malignant struma ovarii treated by ovariectomy, thyroidectomy, and 131I administration

A 36-year-old woman presented with an intraperitoneally disseminated malignant struma ovarii, diagnosed by histopathology and 131I scintigraphy. The serum thyroglobulin level was elevated, and immunoperoxidase staining for thyroglobulin was positive for disease both in the tumor cells lining the follicles and in the colloid. The patient was treated successfully by a bilateral ovariectomy followed by a total thyroidectomy and administration of radioactive iodine. The clinical behavior and the presence of thyroglobulin in both serum and tumor tissue demonstrate the similarity between neoplastic thyroid tissue in the ovary and in the thyroid gland.