Pathology of tumours of the central nervous system

Tumours of the central nervous system (CNS) occur either as intrinsic lesions within the CNS and its coverings, or as metastatic lesions from a primary site outwith the CNS. Primary CNS tumours account for less than 2% of all malignant neoplasms; however, CNS tumours are the second most common group of tumours in children. Histological examination is essential for diagnosis, and is often aided by immunohistochemistry. The World Health Organisation (WHO) classification is important in predicting tumour behaviour and prognosis of primary CNS tumours. This article reviews the main CNS tumour types occurring in adults and children, describes the steps to histological diagnosis and indicates recent advances in CNS tumour analysis.