Mature teratoma in association with neural tube defect (occipital encephalocele): series of four cases and review of the literature.

Both occipital encephalocele and teratomas are midline congenital malformations. Encephalocele is a form of neural tube defect in which there is a congenital defect of the cranium through which occurs a protrusion of brain matter or meninges, while teratoma is a tumor derived from all three germ layers. The association between occipital encephalocele and teratoma has not been reported to date. In the present study, the authors present a series of four such cases.