Struma ovarii associated with Pseudo-Meig's syndrome and high serum level of CA 125; a case report

Struma ovarii is a rare form of ovarian neoplasm derived from germ cells layers in a form of mature teratoma and is composed predominantly of thyroid tissue. The preoperative diagnosis is generally difficult [1]. Although the vast majority of these tumors are benign, they can also mimic malignant ovarian tumors. Elevated tumor markers for a post-menopausal woman presenting with a multilocular adnexal mass, ascites, and pleural effusion can be interpreted as highly suspicious case of malignancy [2]. The diagnosis is usually made postoperatively and by the pathologists. The association of pseudo-Meig's syndrome and elevation of CA125 level to struma ovarii is an extremely rare condition [2] that makes it difficult to differentiate from malignancies [3,4]. In some cases, the tumor produces thyroid hormone and in some cases, hypothyroidism is reported after tumor resection [5].A72-year-old woman with a history of gravida 10, para 10 was referred to department of Obstetrics & Gynecology of Taleghani Hospital. She had a pelvic mass that was from 2 months before, and was admitted to a local hospital complaining of dyspnea. Her medical history had included hypertension since 4 years ago and her other medical history had been normal. In physical examination, she had a top normal size uterine and palpable mass in lower side of abdomen. No lymphadenopathy was detected in auxiliary, supraclavicular or inguinal regions. In paraclinical examination, chest imagings showed massive pleural effusion on right side (Figures 1 and 2). The cytological evaluation for the pleural fluid showed inflammatory cells infiltration and no malignant changes had been detected. Then a chest tube was inserted for the patient to reduce the volume of pleural effusion. The pleural fluid culture for anaerobic and other organisms and its direct smear for Mycobacterium Tuberculosis were negative.Her transvaginal ultrasonography showed multilocular cystic-solid mass on her right ovary measuring 53 mm in diam