[Anaplastic type of Wilms' tumour]

Wilms' tumour, one of the most common solid tumours in children, is classified in groups with favourable, unfavourable and standard risk histology. Anaplastic Wilms' tumour is a representative of the tumours with unfavourable histology. Anaplasia (focal or diffuse) can involve ony component of the tumour but it has no influence on prognosis. Anaplastic Wilms' tumour usually occurs in older children and requires more aggressive therapy. However, if the correct diagnosis is established and adequate treatment applied the prognosis for these children is the same as for Wilms' tumour of standard risk histology.