Giant struma ovarii with pseudo-Meigs’syndrome and raised cancer antigen-125 levels: A case report

BACKGROUND Struma ovarii is a type of monodermal mature teratoma composed entirely or mainly of thyroid tissue, accounting for 1% to 3% of all ovarian teratomas and 0.3% to 1.0% of all ovarian tumors. Of which, struma ovarii with ascites and pleural effusion, called pseudo-Meigs'syndrome and raised cancer antigen-125 levels (CA 125) is even rarer. CASE SUMMARY This paper reports the diagnosis and treatment of a patient of struma ovarii with pseudo-Meigs'syndrome, presenting with the clinical features of ovarian carcinoma: Complex pelvic mass, gross ascites, right pleural effusion and markedly elevated serum CA 125 levels. During the operation, a cystic-solid mass about 20 cm x 10 cm x 5 cm in the right adnexa and a solid mass with the size of 3 cm x 2 cm x 0.1 cm in the left ovary were observed. She underwent right adnexectomy and resection of the left ovarian mass and histopathology revealed a mature left-sided ovarian teratoma and struma ovarii of right adnexal mass. During 1-year follow-up, the patient recovered well, tumor markers and other indicators returned to normal. CONCLUSION The diagnosis and treatment process of this case suggests that the clinical symptoms of struma ovarii with pseudo-Meigs'syndrome are lack specificity, which is easily misdiagnosed. Clinicians should improve the understanding of this disease, enhance the awareness of early screening, and improve the level of diagnosis and treatment.