Abstract
The objectives of this study were to determine the epidemiology of brain tumors during infancy and childhoodand to define and segregate childhood brain tumors vis-à-vis their morphological characteristics. The presentstudy includes pediatric brain tumors, ICD-10 category C71 encountered during 10 years (January 1989 throughDecember 1998) at a tertiary care hospital in Karachi. Eighty one cases were included, 58 (71.6%) in males and23 (28.4%) in females with a male to female ratio of 2.5:1. The cases were divided into 3 age groups eachcovering five years of life (0-4, 5-9, 10-14 years), with the greatest number in the second age group i.e. 5-9 yearsfollowed by the third age group and the 0-4 year age group. The mean age for all cases, both genders was 8.8years (95% CI 7.9; 9.6) with a marginal variation for cases occurring in the cerebrum and cerebellum. Themalignancies occurred at a younger age in the males for each subcategory by site and morphology. Themorphological distribution of cases was astrocytoma (28 cases, 34.6%), primitive neuroectodermal tumor orPNET (40 cases; 49.4%), ependymoma (8 cases, 10%), mixed glioma (4 cases; 5%) and a case ofoligodendroglioma. The 81 malignancies included in this study were further categorized by site into two groups,supratentorial (27 cases; 33.3%) and infratentorial (54 cases; 66.7%). The morphological categorization ofsupratentorial tumors was astrocytoma (17 cases; 63%), ependymoma (5 cases; 18.5%), mixed glioma (2 cases;7.4%). PNET with rhabdoid differentiation, oligodendroglioma and pinealoblastoma comprised 1 case (3.7%)each. The 17 supratentorial astrocytoma were sub-categorized as follows - pilocytic astrocytoma (5 cases; 29.4%),grade II astrocytoma (6 cases; 35.3%); grade III astrocytoma (2 cases; 11.8%), anaplastic astrocytoma (1 case;5.9%) and glioblastoma multiforme (3 cases; 17.7%). The morphological categorization of infratentorial tumorswas astrocytoma (11 cases; 20.4%), medulloblastoma (38 cases; 70.4%), ependymoma (3 cases; 5.6%) and mixedglioma - astroependymoma (2 cases, 3.7%). The morphological sub-categorization of infratentorial astrocytomawas pilocytic astrocytoma (7 cases, 63.6%), with gemistocytic astrocytoma, grade II, grade III and anaplasticastrocytoma comprising 1 (9.1%) case each. The morphological categorization of medulloblastoma was classicalmedulloblastoma (15 cases; 39.5%), desmoplastic medulloblastoma (8 cases; 21.1%), medulloblastoma withastrocytic differentiation (12 cases; 31.5%), medulloblastoma with neural differentiation (2 cases; 5.3%), andneuroblastic medulloblastoma (1 case; 2.6%). The pediatric brain tumors in Karachi reflect a developing countryscenario, with a strong male predisposition and a late presentation with a peak in the 5-9 year age group. Thereis a predominance of medulloblastoma and a paucity of astrocytomas. The current study is a single institutionstudy and needs cautious interpretation. Population-based studies are required to determine the cancer burdendue to pediatric malignancies of the brain in this population and for the morphological categorization of braintumors in Karachi.
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