Abstract
Struma ovarii is a rare form of ovarian neoplasm in a form of mature teratoma and is composed predominantly of thyroid tissue. In the literature review, there has only been 10 cases of this tumor, associated with ascites and pleural effusion (Meig's Syndrome) and increased CA125 so far. In such cases, the tumor mimics malignant ovarian tumor. In this article, the case of a 72-year-old symptomatic woman with a pelvic mass, pleural and peritoneal effusion and high level of serum CA125 is presented. Cytological evaluation for the pleural fluid was performed. She underwent hysterectomy and bilateral salpingo-oophorectomy. The result of pathologic diagnosis is presented in this paper. The patient was well in postoperative period and paraclinical tests including CA 125 were normal as well.