Unraveling the Conundrum: A Rare Case of Mucinous Cystadenoma in the Uterus.

Extra-ovarian recurrence of mucinous cystadenomas (MCs) is a rare phenomenon. This case report presents the first documented instance of a benign MC recurring within the uterine myometrium of a 48-year-old woman. Two years following an oophorectomy for a large left ovarian MC, the patient presented with lower abdominal pain. Imaging revealed a pelvic mass and subsequent surgery identified a cystic lesion arising from the uterine fundus. Histopathological examination confirmed a benign MC. This case underscores the importance of considering a broad differential diagnosis for pelvic cystic lesions, especially in patients with a history of mucinous tumors. It highlights the potential diagnostic challenge posed by such a rare presentation and emphasizes the need for further research into mechanisms underlying extra-ovarian recurrences.