Medulloblastoma presenting as neck tumors in 2 infants.

Extension of neuroepithelial neoplasms outside the neuraxis, though uncommon, is well known and usually follows surgical intervention. More unusual is the brain tumor that appears beyond the bounds of the central nervous system prior to operative manipulation. Two infants presented with soft tissue masses in the neck that proved to be medulloblastomas. Autopsy examination in both infants showed primary medulloblastoma of the cerebellar vermis with extensive spread through the subarachnoid spaces. The neck masses may have been direct extensions from the central nervous system tumors, though this was not proved in either case.