There has been an explosion of knowledge and enormous progress in the fundamental understanding of the biology of cancer in recent years. This has included the realisation that cancer occurs when normal cellular functions are disturbed leading to a malignant phenotype. Much research hasfocussed on understanding the types of disturbances that can occur, the contribution that these abnormalities can make to the development and behaviour of particular cancers and more recently, the recognition that these cellular and genetic abnormalities can provide rational targets for newtherapeutic approaches. Information about the biology of cancers that occur in children has increased in parallel with these more general advances and this book is intended to provide a focus for readers who wish to have an understanding of our current state of knowledge. A international group of editors and contributors provide guidelines on the molecular biology and pathology of paediatric oncology, aimed at clinicians and scientists working in the specialty who wish to understand current developments in molecular pathology as applied to their field. The book is abroad ranging review focusing on the impact of molecular and cytogenetic techniques on our understanding of the aetiology, clinical behaviour, diagnosis and management of paediatric cancer. The first section outlines the laboratory handling of tissue samples, theory and methodology of cytogeneticand molecular techniques and discusses predisposition syndromes. The second section highlights the application of cytogenetic and molecular methods in diagnosis and treatment of the major paediatric cancers.