Papillary Wilms' tumour with carcinoma‐like foci and renal cell carcinoma in childhood

Five cases of Wilms' tumour with prominent papillary formation and focal carcinoma-like epithelium are described. The morphology of these tumours is compared with a group of six renal cell carcinomas in childhood. A link between this type of nephroblastoma and renal carcinoma is suggested but pure renal carcinomas are considered to be a separate category. The biological behaviour of the papillary Wilms' tumours was found to be more aggressive than is generally believed. The course of the disease may be influenced by carcinoma-like structures although this fact is not definitely established. Staging seems to be more helpful in such patients as is the case with renal cell carcinomas. Further studies on this type of Wilms' tumour are needed to establish more consistent data.