Diffuse intrinsic pontine glioma

Additional clinical information: The patient has neurofibromatosis type 1


Findings

Initial CT shows a new central dorsal pontine focus of FLAIR hyperintensity, demonstrating enhancement. One year later, there has been significant increase in the size of a heterogeneously enhancing expansile pontine mass lesion, with extension into the midbrain and along the cerebellar peduncles into the right cerebellar hemisphere.

Differential Diagnosis:
- Pontine Glioma
- Neurofibromatosis Type 1 associated hamartoma or foci of signal intensity
- Brainstem encephalitis
- Acute disseminated encephalomyelitis (ADEM)
- Tuberculoma
- Histiocytosis
- Pontine myelinolysis
- Infarct
- Lymphoma


Diagnosis: Diffuse intrinsic pontine glioma


Key points

Brainstem gliomas
- Represents 12% to 15% of all pediatric brain tumors
- Several types, including diffuse pontine glioma, tectal glioma, focal tegmental mesencephalic
- Histology is usually anaplastic astrocytoma or glioblastoma multiforme
- Does not metastasize outside of the central nervous system


NF1
- Association with tectal and diffuse pontine glioma
- Clinical Presentation:
Presents with headache, ataxia, cranial nerve palsies, hemiparesis
Age of presentation is in children and young adults
No sex predilection
Results in respiratory insufficiency
Treated with chemotherapy and radiation
Poor prognosis in children, with 10 to 30% 5 year survival


Imaging characteristics for diffuse pontine glioma

CT
- Isodense or hypodense, with indistinct margins
- Rare calcification or hemorrhage
- Only 10% will have hydrocephalus
- Variable enhancement

MRI
- Low signal on T1
- High signal on T2
- High signal on FLAIR
- Variable enhancement
- Demonstrates expansion of pons, obstruction of fourth ventricle