Tumors in the kidney region of children may be either benign or malignant. Cystic enlargements of the kidneys are fairly common. The benign growths may appear as adenomas, angiomas, lipomas or fibromas. Cysts occur as congenital cystic kidney; acquired as results of hydronephrosis or of pyonephrosis, or as hydatid cysts. Reports of cases of congenital hydronephrosis without malignancy are included in this study.
Malignant tumors of the kidney are grouped variously. An accepted classification has yet to be made. In general, these cases fall into the group of carcinomas, sarcomas and hypernephromas.
The malignant tumors of the kidney region are the kind which usually occur in young patients. The greatest number of cases occur between the ages of 6 months,and 6 years. Of all malignant growths affecting children, those affecting the kidneys appear to be second in number. D'Espine and Piso constructed a table which sets forth in order of