The pons encompasses both the cerebellar peduncles and the floor of the 4th ventricle.
The pons is the most common site of brain stem gliomas (80% of all brain stem gliomas arise in the pons).
10-15% of tumors arise in the medulla, and even fewer arise from the midbrain (5-10%).
Tumor Location & Frequency:
| Tumour Location | Frequency |
| Pons | 80% |
| Medulla | 10 - 15% |
| Mid Brain | 5 - 10% |
Staging
- There is no widely accepted staging system for brain stem gliomas.
- It is very uncommon for these tumors to spread outside of the brain stem at the time of initial diagnosis. Diffusely infiltrative brain stem gliomas can occasionally be associated with neuraxis dissemination.
