ABSTRACT
Struma Ovarii is a teratoma with thyroid tissue as the predominant (>50%) constituent. It is rare, representing about 2% of all teratomas, and its malignant transformation, less than 5% of struma ovarii. Presenting symptoms are not specific, therefore pre-operative diagnosis of malignant struma ovarii is difficult and most diagnosis of malignant struma ovaii is determined by post-operative histologic findings. Because of the rarity of malignant struma ovarii, there is considerable confusion concerning diagnosis and management. A postmenopausal woman presented with pelvic mass and lower abdominal pain and explo-laparotomy was performed. Then, pathologic report was identified as malignant struma ovarii. We report a case of malignant struma ovarii with brief review of literature