Epidemiology of pediatric primary tumors of the nervous system: A retrospective study of 633 cases from a single Moroccan institution

Abstract Background and purpose There are several reports regarding the epidemiology of pediatric brain tumors. However, little is known about the profile of pediatric brain tumors in Africa especially in Morocco in particular. The authors report the results of epidemiological analysis of a retrospective review of childhood primary brain tumors in a single institution. Methods A retrospective review of all cases of primary brain from 1 month to 15 years diagnosed at the Department of Pathology of the Hospital of Specialities of Rabat between January1991 and December 2009 was performed. Results Six hundred and thirty-three primary tumors of the central nervous system were reviewed with a mean of 33.31 cases per year. According to the gender, 55% of the tumors occurred in males and 45% in females. The mean age was 8.36 years. Of all the tumors, 47% were situated in the supratentorial compartment, 48% in the infratentorial compartment, and 5% in spinal cord. In the infratentorial compartment, 82% of tumors are located in the cerebellum, 15% in the fourth ventricle, 2% in the brain stem and 1% in the cerebellar pontine angle. In the supratentorial compartment, two third of the tumors were located in the cerebral hemispheres and the sellar region. Thus 39% of tumors are located in the cerebral hemispheres followed by the sellar/suprasellar region (30%), lateral and third ventricles (11%), pineal region (8%), meninges (5%), choroid plexus (4%), and optic chiasma/tracts (3%). The most common types of tumors diagnosed were pilocytic astrocytoma and medulloblastoma together accounting for nearly half of the cases (46%) (23.1% and 22.9% respectively), followed by craniopharyngiomas (9%), ependymomas grade II (6.5%), glioblastomas (6%), astrocytomas grade II (4.4%), ependymomas grade III (3.9%). The other tumors represent 22.6%. Conclusion We think that our results reflect fairly well the incidence of tumors of the nervous system in children due to the fact that this study was performed through many years in a single institution with a homogeneous neuropathological approach.