[Struma ovarii, a rare form of ovarian tumor].

Struma ovarii, a rare form of ovarian tumor, represents less than 3% of ovarian teratomas. The peak frequency occurs during the fifth decade of life. Diagnosis is usually a surprise of pelvic ultrasound or histological analysis. Surgery is the main mode of treatment and prognosis is excellent. Struma ovarii can be associated with thyroid biology abnormalities, or exceptionally become malignant, and thus managed as a thyroid cancer.