(ĕn‵dō-mē‵trē-ō'mă )

[endo-, within, + metra, uterus, + oma, tumor]

A benign tumor comprised of ectopic endometrial cells. It is found most frequently in the ovary, the cul-de-sac, the rectovaginal septum, and the peritoneal surface of the posterior portion of the uterus.