Diffusely infiltrating brainstem gliomas: a report of the diagnostic difficulties in 2 cases.

Brainstem gliomas seem to present in 2 distinct ways. More commonly they are localized to 1 portion of the brainstem and present with signs that are both localizing and lateralizing. These are usually fairly easy to image neuroradiologically. The rarer diffusely infiltrating variety manifest a slowly building array of findings pointing to all levels and both sides of the brainstem. Our 2 cases exemplify the diffuse variety. They were clinically typical, and the CSF pressure and protein were elevated but the neuroimaging abnormalities were so subtle that they were originally overlooked. This subtlety of neuroradiologic abnormality resembles that found in gliomatosis cerebri.