GLIOMA-BRAIN STEM-CHILD

Brain stem glioma is a cancer that is predominantly found in children and young adults. These tumors account for 15 percent of all central nervous system tumors of children. Fifty percent occur in children under the age of 15.

This type of brain cancer often has a dire prognosis, especially those tumors that express a p53 genetic mutation Only about 10 to 15 percent of children with the most common kind of brainstem gliomas are alive three years after diagnosis.

Survival comes at a price for many patients. Survivors may have severe and permanent neurological, cognitive, endocrine and/or psychologicaldeficits arising from the treatment itself, especially from the high doses of radiotherapy necessary to control the tumor. Thus, deciding on treatment for youngsters with brainstem cancer often involves heartrending dilemmas for the parents and guardians of these children. It also sometimes leads to thorny legal problems, particularly when parents try to opt out of the system and pursue non-conventional alternatives.

Brainstem gliomas are classed as "infratentorial" tumors. This means that they arise below the structure known as the "tentorium".  The tentorium is a thick sheet of fibrous tissue that divides the cranial cavity into two compartments. The upper compartment - the compartment above the tentorium (supratentorial) is occupied by the cerebral hemispheres, or upper part of the brain. The lower compartment (infratentorial) is occupied by the brain stem, including the cerebellum and the uppermost part of the spinal cord.

Brainstem gliomas are typically high-grade (aggressive) and diffuse - that is to say, they are not discrete, self-contained "lumps", but spread outward, invading surrounding tissue widely in a way that makes them almost impossible to remove completely by surgery alone. They are typically diagnosed by radiography rather than by biopsy. 

The exceptions to this general principle are a small subset of tumors that include focal, exophytic, tectal and cervicomedullary tumors, all of which are relatively low-grade (less aggressive).