Two massive congenital intracranial immature teratomas with neck extension.

In this report we detail two congenital intracranial immature teratomas, noteworthy for their massive intracranial growth and extension through the skull with compromise of neck structures. Cytogenetic studies were done in both cases on the fetuses and their tumors and are the first in the literature. Few previously reported congenital intracranial teratomas have been described with neck extension. In both cases, polyhydramnios was detected by prenatal ultrasonography and was possibly caused by the laryngoesophageal and/or brainstem distortion by neoplasm. Possible reasons for such excessive, unchecked growth of teratomas in the fetal period are discussed.