Abstract
BACKGROUND: Although uterine fibroids are a common gynecologic neoplasm, uterine diverticulum accompanied by a uterine fibroid is unique. In addition, pregnancy complicated with uterine diverticulum is extremely rare. We experienced a case of a uterine fibroid that was associated with a uterine diverticulum that enlarged during pregnancy and puerperium. CASE PRESENTATION: A 25-year-old nulligravida woman had an abnormal uterine cavity surrounded by myomatous mass. After natural conception, the mass and pouch had enlarged during pregnancy. Six months after elective cesarean delivery, she underwent laparotomy because of abdominal pain caused by the myomatous mass and the fluid inside. The tumor was connected to the midline of the posterior wall of the normal uterus. The resected tumor was pathologically diagnosed as leiomyoma and diverticulum. CONCLUSIONS: Pregnancy can stimulate uterine fibroids to form uterine diverticula. Resection of the diverticulum and fibroid is a useful option for symptomatic patients with desired future fertility.