Diastematomyelia associated with teratomas. Report of two cases.

Diastematomyelia, a complete or incomplete sagittal division of the neural axis into halves, is usually accompanied by a number of other malformations. However, true teratomas arising in dorsal juxtaposition to the spinal axis and associated with diastematomyelia are extremely rare. In this paper, two infants with this neoplastic-malformative complex are discussed. The two most prevalent hypotheses in the pathogenesis of diastematomyelia are reviewed. The hypothesis of a persistent neurenteric canal continues to be generally accepted, but, until more is known about the pathogenesis of extragonadal human teratomas, it is not possible to say how these neoplasms relate to the associated spinal cord malformation. Individually, each of the lesions present is extremely rare; it is possible that their concurrence in two patients may not be purely coincidental.