Benign and malignant struma ovarii.

Three cases of struma ovarii are reported, two of which were benign, and one which was malignant. Immunoperoxidase studies confirmed that the tumors secreted triiodothyronine and thyroxine, but no carcinoembryonic antigen nor alpha-fetoprotein. In the case of the malignant struma ovarii, the patient's thyroid was histologically normal, and thus the possibility of a metastasis to the ovary from a primary thyroid carcinoma was excluded.