Mammillo-hypophyseal duplication (diplo-mammillo-hypophysis).

A first-time description is given of a unique combination of congenital deformities encountered in a female infant born in the 35th week of gestation and surviving for minutes only. The principal malformations comprised duplicity of the hypophysis cerebri and mammillary bodies, olfactory aplasia, agenesis of corpus callosum, Dandy-Walker syndrome, thoracolumbo-sacral rachischisis and hydromyelia, associated with palato-gnatho-cheilo-schisis, defects in the pericardium and cardiac interventricular septum and gross maldevelopment of the diaphragm. Of these cerebral anomalies, we have chosen to concentrate on the condition which we denominate "diplo-mammillo-hypophysis" (mammillo-hypophyseal duplication) as the object of this study. On grounds of embryonal development it is considered to have come about during the first half of the 2nd month of gestation. The likely genesis of the pathologic findings is discussed.