Struma ovarii is an uncommon ovarian teratoma comprised predominantly of mature thyroid tissue. The combination of pseudo-Meigs' syndrome, and elevation of CA 125 to the struma ovarii is a rare condition that can mimic ovarian malignancy. We reported a case of benign struma ovarii, presenting with the clinical features of advanced ovarian carcinoma: complex pelvic mass, gross ascites, bilateral pleural effusion and markedly elevated serum CA 125 levels. The patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. Ascites and pleural effusion were not evident and the CA 125 levels returned to normal following surgical excision. A systematic review of reported cases of coexistent benign struma ovarii, pseudo-Meigs' syndrome and elevated serum CA 125 was performed. Struma ovarii accompanied by pseudo-Meigs' syndrome and elevated serum CA 125 should be considered in the differential diagnosis of ovarian epithelial cancer.
Keywords: CA 125; ascites; mature teratoma; pleural effusion; pseudo-Meigs’ syndrome; struma ovarii.