Struma ovarii. Report of a malignant and a benign case

: Struma ovarii is a rare type of ovarian teratoma, composed entirely or in part of thyroid tissue. Malignant Struma ovarii were exceptional. We report one benign and one malignant cases of Struma ovarii. We insist upon their rarety and the difficulty of preoperatory diagnosis. Prognosis is good after surgery.