Glial heterotopia of the uterine cervix: DNA genotyping confirmation of its fetal origin.

Uterine glial heterotopia is a rare, yet biologically intriguing lesion, mostly involving the cervix. Although an implantation of the fetal brain tissue is widely accepted as the etiology, there has been no confirming evidence to support this hypothesis. We investigated a case of polypoid glial heterotopia of the uterine cervix in a 42-year-old woman who underwent an elective termination of pregnancy of a Down syndrome fetus. One year earlier, the patient had a pregnancy termination of a fetus with Klinefelter's syndrome. Gross and microscopic examination revealed a 2.5 cm polypoid cervical lesion consisting of lobulated mature glial tissue covered by endocervical glandular epithelium. The neural nature of the lesion was confirmed by glial fibrillary acidic protein and S100 immunohistochemistry. DNA genotyping of the cervical polyp, maternal, first and second fetal tissue samples showed an identical genetic profile between the cervical glial tissue and the first aborted fetus. Genotyping also attested the presence of Klinefelter's syndrome in the first gestation and Down syndrome in the second gestation. Therefore, this molecular case investigation confirms the fetal origin of uterine glial heterotopia.