[Central nervous system tumours in childhood: their clinical pathological aspects]

Paediatric tumours affecting the central nervous system (CNS) constitute the second most frequent group of tumours at this age. Taking the WHO 2000 classification as our starting point, our intention was to describe the more important clinical and pathological features in the differential diagnosis of the different tumourous entities with the highest incidence in childhood. We highlight, above all, the characteristics that justify the need for a smooth flow of information between neurologists, neurosurgeons, neuroradiologists, neuropathologists and oncologists. We do not deal with familial tumourous syndromes, genetic aspects or clinical information derived from analyses of molecular alterations.

Among CNS tumours, enough age related differences exist to be able to consider those appearing during childhood in their own right. Their topographic specificity is very characteristic and while 50% of them are infratentorial, 90% of those that occur in adults are supratentorial. Embryonic tumours are very frequent in childhood, but rare in adults, and the opposite happens with meningiomas. They are also different as regards their histological features, clinical characteristics, the early tendency to spread throughout the nervous system in the course of the disease and their biological behaviour. These data make us think that, in the pathogenesis of brain tumours in children, the molecular and epigenetic factors involved are different from those at play in the case of adults.

A correct diagnosis requires a multidisciplinary approach and an understanding of the histological criteria and nomenclature by the health professionals involved in treating these patients.