The incidence and distribution of spinal metastases in children with posterior fossa medulloblastomas.

Myelography was performed postoperatively in 34 children with posterior fossa medulloblastomas. In 15 patients, there was myelographic evidence of intraspinal spread. This was more common in younger patients. The spread varied from a single nodule to extensive disease with spinal block. The lumbosacral canal was affected most often. Three patients with positive myelograms had negative cerebrospinal fluid cytology. Only one patient had symptoms referrable to the spine.