Heterotopic brain cyst from middle cranial fossa to submandibular region.

The case of a newborn boy with a congenital cystic neck mass causing respiratory distress is reported. This lesion extended from the submandibular region through a bone defect to the middle cranial fossa but remained totally extradural. There was no underlying brain abnormality. The cyst was composed mainly of mature neuroglial tissue, with some ependymal and choroid plexus elements, and was diagnosed as heterotopic brain. After 8 years' follow-up, the child still has no deficits.