Struma Ovarii is one of the types of mature teratoma, with predominant thyroid tissue (>50%). It occurs in 1% of all cases of ovarian tumors and in 2.7% of dermoid tumors. There are no specific clinical, radiological or serum markers for this rare pathology. Rarely it may be accompanied by ascites and the increased level of CA-125. In general Stuma Ovarii is clinically defined as an ovarian malignancy. It is diagnosed only by histopathological examination of the surgical material. Diagnosis of Struma Ovarii dictates the need for advanced research of the thyroid. Struma Ovarii is mostly benign. Its malignant transformation occurs in only 5% of all cases, That leads to further management planning analogous to the treatment of thyroid cancer. The case of malignant Struma Ovarii of the 50-year-old woman, which led to total thyroidectomy and radioactive iodine therapy - is described.
Keywords: Papillary thyroid carcinoma; Struma Ovarii; thyroid multinodular hyperplasia.