[Congenital malignant neoplasms].

In order to determine the proportion of congenital neoplasias, a study of 1 076 malignant neoplasias was carried out at the Pathology Department of the Hospital Infantil de Mexico. As unquestionably congenital malignant neoplasias were considered those detected since birth and as possibly congenital, those identified during the first year of life of the patient. As a whole, in this series of neoplasias, approximately one case was found of the sum of the congenital group and the possibly congenital, to 4.5 of the total series. However the proportion of the group of congenital malignant neoplasias and that of possibly congenital varied for each type of neoplasias in particular. Excluding malignant neoplasias of hematopoietic tissues, retinoblastoma, nephroblastoma and neuroblastoma were the malignant neoplasias most frequently found.