Struma ovarii with elevated ca-125 levels and ascites mimicking advanced ca ovary.

Struma ovarii is uncommon tumor of ovary which can mimic as advanced carcinoma of ovary. Thyroid tissue is relatively frequent constituent of mature ovarian teratoma. Case of struma ovarii masquerading as cancer of ovary in a female aged 63 yrs showing complex large unilateral multilocular adnexal mass with elevated CA 125 (more than 1721 IU/L) and massive ascites mislead treating surgeons for long time. Clinicians were virtually clueless about preoperative diagnosis. Combination of ascites has been seen in one third cases but association with raised CA 125 is rare(only 8-10 cases so far). This case developed hypothyroidism one week after surgery.