An immature teratoma that arises from the ovary and occurs in children. The disease is childhood immature teratoma of ovary (MONDO_0004082). Also known as: childhood immature ovarian teratoma, childhood immature teratoma of the ovary, childhood ovarian immature teratoma, immature ovarian teratoma of childhood, paediatric immature ovarian teratoma, paediatric immature teratoma of ovary, paediatric immature teratoma of the ovary, paediatric ovarian immature teratoma.