Pseudo-Meigs syndrome and elevated CA125 associated with struma ovarii.

BACKGROUND: Struma ovarii is a rare form of ovarian neoplasm composed entirely and predominantly of thyroid tissue. The association of pseudo-Meigs syndrome, elevation of CA125 and hyperthyroidism to struma ovarii is a rare condition.

CASE: We report an unusual presentation of a postmenopausal woman with benign struma ovarii associated with pseudo-Meigs syndrome, hypertiroidism, and elevated CA125 serum level, and a large complex right pelvic mass thereby mimicking an ovarian cancer.

CONCLUSIONS: Struma ovarii is a rare cause of ascites, hydrothorax, elevated CA125, and hyperthyroidism. This rare condition should be considered in the differential diagnosis in patients with ascites and pleural effusions but with negative cytology.