Struma ovarii.

Objective: To review the clinicopathological experience of patients with benign and malignant struma ovarii.
Method: A retrospective institutional analysis of 2 patients with malignant and 14 patients with benign struma ovarii, treated during a period of 20 years.
Result: The patients with struma ovarii constituted 1.0% of all ovarian neoplasms in our institution (16/1501). Four percent of the germ cell tumors were calculated to be of struma ovarii (16/382). The stages of the malignant cases were recorded as 1A and 1C. Besides detection at early stage, a biologically low grade tumor was encountered as well. Although 5 of the patients had goitre, none of them had hyperthyroidism. None of the patients had a bilateral tumor. However, in 2 patients, a serous cystadenoma and dermoid cyst were found in the contralateral ovaries. The preoperative and intraoperative diagnosis of malignant struma ovarii proved to be difficult since 2 patients subjected to radical surgery according to suspicious frozen section reports in this series later were found to be benign struma ovarii.
Conclusion: The low metastatic potential and slow progression rate of malignant struma ovarii support conservative surgery especially in young patients who have not yet completed their families.