The large number of articles which have appeared during the past ten years on the subject of malignant renal tumors in children is evidence of the widespread interest in this subject. Not only does the urologist regard this subject with deep concern, but the pediatrician, the roentgenologist and the pathologist are equally interested. One of the results of this trend toward intensive clinical and pathologic study of malignant renal tumors on the part of the aforementioned specialists has been the uniform terminology now used in reporting the cases.
In a previous communication1 I called attention to the fact that these tumors have certain characteristics which the ordinary renal tumors do not possess and that these may be enumerated as follows. 1. Although a few cases have been reported in which the tumor occurred in adults, the fact remains that it is essentially a disease of infancy and childhood. 2.