Malignant follicular thyroid carcinoma arising in struma ovarii: A case report and review of the literature

Struma ovarii is a rare (2.7%) ovarian teratoid tumour that can be diagnosed only when thyroid tissue is the predominant element. The malignant struma ovarii is even more rare, and makes up 5% of all cases of struma ovarii. Here we report a case of malignant struma ovarii. A 76-year-old women gravida 3 and parity 3, referred to our gynecologic oncology clinic. She underwent bilateral salphingo-oophorectomy suspicious with malignancy in another hospital where she was referred from. Tumor markers were reported as Ca 19.9: 8.2 U/ml, Ca 125: 6.8 U/ml, α-feto protein: 1.2 IU/ml and CEA: 4.3. The patient underwent hysterectomy and omentectomy in our hospital. Frozen section pathology was consistent with malignancy. Final pathology revealed an extensive proliferation of thyroid follicular epithelium. Two months after the operation, the patient was died of disease. Here, we report the case of malignant struma ovarii including foci of follicular thyroid carcinoma