Stiller CA., Bleyer WA.
© 2004 by Taylor & Francis Group, LLC. Brain and spinal cord tumors are the most frequent type of solid tumor in children under 15 years of age and second only to leukemias among all malignancies. In most populations, they represent upwards of 20 per cent of all childhood cancers.1 These tumors cannot be considered together as a single entity, however, as they are of several distinct histological types, with their own patterns of incidence, and cannot be assumed to have a common etiology. In the International Classification of Childhood Cancer (ICCC),2 which groups childhood tumors mainly on the basis of morphology, diagnostic group III,“CNS and Miscellaneous Intracranial and Intraspinal Neoplasms,” contains six subgroups, namely (a) ependymomas (including choroid plexus tumors), (b) astrocytomas, (c) primitive neuroectodermal tumors (PNETs), (d) other gliomas, (e) other specified neoplasms (including pituitary adenomas, craniopharyngiomas, pineal parenchymal tumors, gangliogliomas, and meningiomas), and (f) unspecified neoplasms.The non-malignant tumors are concentrated in subgroups a, e, and f. A further ICCC subgroup, Xa, comprises intracranial and intraspinal germ-cell tumors and also includes a sizeable proportion of non-malignant tumors.Non-malignant tumors of blood vessels and peripheral nerves, including haemangiomas, haemangioblastomas, and schwannomas, are not included in the ICCC.