The pathology of nephroblastoma

Abstract

This article summarises the approach to specimen processing, reviews the pathological features and briefly discusses the clinical features and genetics of nephroblastomas. The pathological assessment provides essential information necessary for determining further management, therefore great care should be taken to optimise processing and prevent artefacts. The classical nephroblastoma is triphasic, consisting of blastema, epithelium and stroma. However, monophasic and biphasic forms are not uncommon. Heterologous cell types and varying degrees of cellular differentiation are frequent findings which sometimes contribute to diagnostic difficulties. Cystic partially differentiated nephroblastoma has specific pathological and behavioural characteristics and therefore must be distinguished from nephroblastomas with cystic areas. The presence of anaplasia must be further qualified as either focal or diffuse because diffuse anaplasia is an indicator of adverse prognosis. Although nephroblastomas may be regarded as one of the successes in oncology, there is still much knowledge that remains to be gained.