study was conducted between 2000 & 2002, 50 children with histopathologyically verified medulloblastoma and cerebellar astrocytoma in neurosurgical department of Surgical Specialties Hospital. Ages ranged from 2-19 years, peak incidence between 5-10 years. No significant gender differences found.
CT scan confirmed features of medulloblastoma: midline location, well defined margin & hyperdensity of lesion with homogenous enhancement after I.V. contrast infusion. In cerebellar astrocytoma, 60% were midline tumor, most of which were solid & 40% were hemispheric lesion, most of which were cystic. Calcification on CT scans seen more in medulloblastoma.
Shunt operation was the main procedure conducted for treatment of hydrocephalus associated with these tumors, but other CSF diversion procedures, especially safety burrhole at time of tumor resection was carried on in cystic lesion located off the midline. Total removal was achieved in 46.7% of children with medulloblastomas & 50% of children with cerebellar astrocytomas. Brain stem violation was evident more in medulloblastoma & was the main factor behind the incomplete tumor removal in significant number of cases that adversely affected the outcome.
postoperative complications (pseudomeningocele, cerebellar mutism, meningitis, CSF leak, cranial nerve palsy…etc.) encountered more in children with medulloblastoma.
Mortality rate was 6.7% in medulloblastomas & 10% in cerebellar astrocytoma. The cause of death in patients with medulloblastoma was meningitis & patients with cerebellar astrocytomas was brain stem injury.
early diagnosis & total removal of tumor with proper postoperative care would essentially decrease the postoperative morbidity & mortality