Origin of uterine teratoma differs from that of ovarian teratoma: a case of uterine mature cystic teratoma.

Mature cystic teratomas are usually found in the ovaries and rarely in the uterus. Most teratomas of the uterus are of cervical origin. There are only a handful of reports to date of uterine teratomas arising from uterine corpus. The teratomas of the ovaries and the cervix are thought to be of parthenogenetic origin from oocyte after the completion of the first division. However, the origin of a uterine teratoma has not been established by molecular methods. In this study, we report a 46-year-old woman with a teratoma within uterine corpus. Computed tomography scanning and histological studies after tumor resection confirmed the diagnosis of teratoma. The DNA profiles of normal uterine tissue and teratoma tissue were compared using short tandem repeats analysis and showed that the teratoma did not originate from the parthenogenetic process. Our results suggest that the origin of this uterine teratoma is most likely pluripotential stem cell of uterus or primordial germ cell before meiosis I.