Mesothelial Cyst in the Uterine Myometrium: A Rare Localization

Mesothelial cysts in the uterus are exceedingly rare. A 41-year-old patient presented with complaints of abdominal pain, and transvaginal ultrasonography revealed an enlarged uterus with a hypoechoic intramural cystic mass measuring 7.2 × 3.3 × 3.6 cm in the posterior uterine corpus. Suspecting a degenerated leiomyoma, the patient underwent a total laparoscopic hysterectomy and bilateral salpingectomy. Intraoperatively, a cystic lesion approximately 7 cm in size was observed within the myometrium of the posterior uterine wall. Pathological examination, supported by immunohistochemical findings, confirmed the diagnosis of a mesothelial cyst. Mesothelial cysts can mimic various clinical and radiological entities, and definitive diagnosis is typically established through pathological evaluation following complete excision of the lesion.