A study of childhood brain tumors based on surgical biopsies from ten North American institutions: sample description. Childhood Brain Tumor Consortium.

The Childhood Brain Tumor Consortium has collected an extensive amount of neuropathologic and clinical information under rigorously controlled conditions about 3,291 children with brain tumors. In this overview of the entire sample, five observations are prominent: 1) many tumors involve more anatomic sites at the time of the first surgical exploration than previously recognized; 2) one-third of infratentorial tumors involve both the brainstem and the cerebellum; 3) the spinal compartment is involved primarily, or in combination with the posterior fossa, in 11% of childhood brain tumors; 4) 43.2% of childhood brain tumors are limited to the posterior fossa; 5) only a few World Health Organization diagnoses account for most brain tumors in children, and 6) there is a male predominance over all ages for infratentorial tumors. Subsequent reports will describe observer variability of participating neuropathologists, correlates of clinical and histologic information, the search for homogeneous subtypes of tumors, and prognostic factors.