Pathology of common childhood tumours

Paediatric pathology is a specialized discipline based in children's hospitals. Children are not merely small adults; they present with many unique pathologies and special consideration must be given to this fact when dealing with malignancy. Cancer in children and adolescents is rare, and the patient should be referred to a specialist centre in order to ensure the best outcome. The paediatric pathologist works within a multidisciplinary (paediatricians, paediatric surgeons, paediatric radiologists, neurologists, geneticists, molecular biologists) team. The diagnosis of a particular malignancy involves close correlation with the radiological findings, clinical features and molecular and cytogenetics. Molecular techniques (e.g. polymerase chain reaction, fluorescence in situ hybridization) are essential for establishing a diagnosis and providing prognostic information. The leukaemias account for about one-third of childhood malignancies; about 80% of these are acute lymphoblastic leukaemia. Tumours of the brain and spinal cord account for about 25% of cases and the lymphomas (Hodgkin's, non-Hodgkin's) account for about 10%. This review focuses on neuroblastoma, Wilms' tumour, retinoblastoma, hepatoblastoma, Ewing/PNET and the sarcomas. The clinical features, typical histological findings, cytogenetics and management of each neoplasm are discussed briefly.