Ectopic thyroid cancer in the ovary – unresolved issues of diagnosis and treatment of struma ovaria maligna

Struma ovaria is an ectopic localization of mature thyroid gland tissue in the ovaries. This rare form of monodermal teratoma is mostly a benign pathology. Primary malignant tumors of the thyroid gland in the appendages of the uterus are represented by thyroid carcinomas. Due to the rare pathology (less than 1 % of all tumors), insufficient information in the literature, lack of generalized recommendations and personal experience, doctors make many mistakes during the treatment of patients with struma ovary. The aim of the work is to demonstrate a rare clinical observation of primary papillary thyroid cancer in the ovary and to discuss the mistakes that were made during treatment. Case report. 5 women with a histologically confirmed diagnosis of struma ovary were under our observation. In 4 lesions were benign. One patient was diagnosed with ectopic thyroid carcinoma. The medical history of a 70-year-old woman who underwent hysterectomy without further treatment in a specialized oncology center for primary papillary thyroid cancer in the ovary is presented. Conclusions. When managing patients with malignant struma ovary, clinicians mistakenly do not use the guidelines developed for the diagnosis and combined treatment of highly differentiated thyroid carcinomas, regardless of their eutopic or ectopic localization.