ABSTRACT
Epidemiology/aetiology Nephroblastoma is by far the most common renal neoplasm of childhood, although other entities exist (Table 21.1). In the older literature, many of these other lesions, which are now recognised as separate entities, were classified as favourable or unfavourable variants of Wilms’ tumour, examples being clear cell sarcoma of the kidney (CCSK) and renal rhabdoid tumour (RRT), both of which were previously categorised as unfavourable histology patterns of Wilms’ tumour.
