Patient: Female, 72Final Diagnosis: Benign ovarian mucinous cystadenomaSymptoms: Difficulty breathing and ambulation • heartburn • reflux • early satiety • nauseaMedication: —Clinical Procedure: Total abdominal hysterectomy along with bilateral salpingo-oophorectomySpecialty: Obstetrics and GynecologyObjective:Rare diseaseBackground:Mucinous cystadenoma is a benign cystic ovarian tumor arising from the surface epithelium of the ovary; it usually presents with vague, unspecific abdominal symptoms. If not detected early, they have the potential to grow to a substantial size and can present with huge abdominal distention leading to various compression symptoms. Mucinous cystadenomas most commonly occur in the third to sixth decades of life, and rarely occur in extremes of age. The reported incidence of giant ovarian cystadenoma in postmenopausal women is low or relatively unknown due to widespread use of ultrasound and other radiological imaging modalities these days. Here, we report a case of giant mucinous cystadenoma in a 72-year-old postmenopausal woman with multiple comorbidities.Case Report:We present the case of a 72-year-old postmenopausal high-risk patient who presented with a huge abdominal distention which started gradually 1 year before. Abdominopelvic ultrasound showed a left giant multiloculated abdominal cyst. An intact 27-kg ovarian cyst was removed, and a total abdominal hysterectomy (TAH) along with bilateral salpingo-oophorectomy (BSO) was performed. The final histopathological report showed a benign ovarian mucinous cystadenoma.Conclusions:Mucinous cystadenoma is a benign neoplastic disease that can reach a massive size. They are rare in the post-menopausal age group, but when they do occur, they pose a diagnostic and therapeutic challenge. This case report highlights the importance of early detection and management of adnexal masses in postmenopausal high-risk patients to decrease preoperative and postoperative complications and improve quality of life.