Abstract
Introduction: Struma ovarii is a rare ovarian tumor characterized by containing either entirely or predominantly thyroid tissue (> 50%). It accounts for less than 1% of all ovarian tumors and approximately 3% of ovarian teratomas. The condition was first described by Von Klden in 1895. Case Presentation: In this report, we described a 50-year-old Afghan menopausal woman who referred to our hospital with a 5-month history of weight loss, anorexia, hyperthyroidism, abdominal distension and sinus tachycardia. Abdominal radiological findings revealed left adnexal large multilocular cystic lesion and the patient’s CA-125 serum level was high. Preoperatively, the clinicians suggested a diagnosis of ovarian cancer based on the symptoms, radiological findings and high level of CA-125 serum. However, postoperatively, histopathological examination revealed the lesion to be a benign struma ovarii. Conclusions: Association of struma ovarii with CA-125 and hyperthyroidism is an extremely rare case and are usually misdiagnosed preoperatively due to nonspecific clinical manifestations, and indistinguishable imaging studies, and should be kept in the differential diagnosis of all ovarian cystic lesions. An exact diagnosis is only made by postoperative histopathological examination, and complete surgical resection of the lesion is considered the optimal treatment.