Overview Flashcards
What is the prevalence of brainstem gliomas (BSGs) in relation to pediatric CNS tumors overall?
BSGs comprise 10%–20% of pediatric primary CNS tumors (<2% of adult CNS tumors).
What is the peak age of presentation for BSGs in children? What is the sex predilection?
The peak age of BSG presentation in children is 5–9 yrs. Males are more commonly affected than females.
What are the 2 classes of BSGs? Where are they most commonly located, and what is the prognosis?
The 2 classes of BSGs are focal and diffuse:
Focal (20%): in the upper midbrain/lower medulla; best prognosis
Diffuse (80%): in the pons and upper medulla; infiltrative and worst prognosis
What are the anatomical subdivisions of BSGs?
Diffuse intrinsic pontine glioma (DIPG), exophytic medullary glioma, and midbrain or tectal glioma
What BSG histology most commonly involves the medulla? The pons? The midbrain?
BSG that arise from midbrain, medulla, and cervicomedullary junction are typically low grade (grade 1 or 2) and are focal, discrete, well-circumscribed tumors without local invasive growth or edema. Pontine gliomas are predominantly diffuse, high-grade, and locally infiltrative.
What mutation is present in most DIPGs?
Up to 85% of DIPGs have a K27M mutation in a gene coding for histone 3. (Cohen et al., Neuro-Oncology 2017)
Is grade prognostic for outcome in DIPG?
No. Although most DIPGs are high-grade, up to one-quarter are low grade and have a similarly dismal prognosis.
What is the median OS for DIPG?
9–11 mos
What is the median OS for focal BSGs?
Tectal gliomas: more than 10 yrs
Other than tectal gliomas, focal BSGs tend to behave like gliomas elsewhere in the brain and have OS reflecting the underlying histology
How common are brainstem gliomas in children and adolescents, and what histologies are most frequently seen?
Brainstem gliomas comprise roughly 10% of all intracranial tumors in children. The incidence peaks between ages 5 and 9, and is seen more often in males than females. Diffusely infiltrating brainstem gliomas are most common, comprising 75% to 85% of brainstem neoplasms in children and adolescents (15%–25% are focal or “exophytic”). High-grade astrocytomas comprise 70% to 80%.
What is the prognosis in terms of median overall survival in children with brainstem gliomas?
What are poor prognostic factors?
The prognosis is very poor, with a 1-year average median survival. The disease is fatal in greater than 90% of patients. Diffuse infiltrating, high grade, and younger age bode for worse prognosis. Patients with focal disease have a 10-year OS of 50% to 70%. Dorsally exophytic and tectal lesion locations are considered more favorable.
