Struma ovarii coexisting with recurrent uterine fibroids in a postmenopausal patient

Introduction: Ovarian teratomas are ovarian tumors that originate from primordial germ cells. Struma ovarii (SO) is a very rare specialized monodermal variant of the mature cystic teratoma, which consists exclusively or predominantly of mature thyroid tissue and occurs most commonly in premenopausal women. Case Report: We hereby report the rare case of a 70-year-old postmenopausal woman who presented with vaginal bleeding and abdominal distention 20 years after the menopause. She was found to have a huge uterine mass, hemorrhagic ascites, and a left adnexal cystic mass with solid areas mimicking a malignancy. Histological analysis of the surgical specimens confirmed a SO coexisting with recurrent uterine fibroids. She had a total abdominal hysterectomy and bilateral salpingo-oophorectomy with a good outcome. Conclusion: Benign SO, a very rare variety of specialized monodermal teratomas, can coexist with ascites and large recurrent uterine fibroids several years after menopause, mimicking malignancy. Timely diagnosis and excision of both tumors via an abdominal hysterectomy and bilateral salpingo-oophorectomy resulted in a good outcome in our patient.