Wilms' Tumor of Infancy and Childhood

When one refers to malignant disease of the kidney in infancy and childhood one is referring to Wilms' tumor, as other types of renal neoplasms, such as hypernephroma, are practically unheard of in the early years, although Wilms' tumor is reported with some frequency in adults. The term “Wilms' tumor” has been selected from the host of synonyms for this neoplasm, which constitutes about 20 per cent of all malignant tumors of childhood, as it is the most familiar designation and the one in most common use. In reviewing the literature, it is surprising to find how many of these cases are hidden under such names as carcinosarcoma, adenosarcoma, embryonic adenosarcoma, embryonic nephroma, malignant nephroma, myosarcoma, adenomyosarcoma, rhabdomyoma, nephroblastoma, spindle-cell sarcoma, and mixed tumor. The wealth of descriptive terms for this single lesion reflects the varied histologic picture that it may present. The clinical and pathologic aspects of the tumor are firmly settled, the two points of controversy being the pathogenesis and the treatment. This paper will not attempt to resolve either of these disputes. Facts and figures from the literature and from personal experience will be presented, and the reader may reach his own conclusions. Histogekesis The earliest conception of Wilms' tumor was that it was a carcinoma, its mixed nature first being recognized by Eberth in 1872. It was his opinion that the tumors arose from inclusions of the wolffian body within the developing kidney. A little later in the same century Cohnheim came forward with his cell-rest theory; he believed that the origin was from aberrant germ plasm, the multiple potentialities of the cells accounting for the wide range of tissues found in the tumors. Some time later, other investigators advanced the theory that the neoplasms were of endothelial origin and that the various tissues observed in them were the result of a metaplasia on the part of the endothelial cells. A derivation from the nephrotome, the anlage of the wolffian body, has also been suggested, but this theory leaves some unanswered questions. The nephrotome is a well developed embryonic structure and one can see how it might be responsible for the acinar, tubular, and abortive glomerular structures of the kidney, but it is difficult to imagine it giving rise to such tissues as muscle, fat, cartilage, or bone. The most logical idea seems to be that proposed by Wilms in 1899. He reasoned that, since a variety of tissues enter into the make-up of these neoplasms, they must arise from a very embryonic type of cell that has multipotentialities for forming various tissues and structures. Such a cell is found in the embryo prior to the formation of the nephrotome.