Medulloblastomas in childhood: postsurgical evaluation with myelography and cerebrospinal fluid cytology.

Thirty-one children with medulloblastoma treated at the Children's Memorial Hospital have been evaluated with both postoperative myelography and cerebrospinal fluid (CSF) cytological studies. Computed tomography of the spine following myelography was used in an attempt to increase sensitivity. Each study was done 30 days after radical resection of the posterior fossa tumor, and just prior to the spinal irradiation. Only 3 (9.6%) showed positive results for spinal subarachnoid seeding by both myelography and CSF cytology. In 2 of these patients, preoperative head CT showed evidence of intracranial subarachnoid seedings. The incidence of positive myelographic finding in our series is lower than reported ones, and neoplastic cells are detected in the CSF only when the myelography shows visible disease.