Overview Flashcards
What is the typical age distribution of pts diagnosed with optic pathway gliomas (OPGs)?
OPGs occur mainly in children, with 90% diagnosed before age 20 and 75% before age 10.
OPG represents what % of all CNS tumors in children?
OPG represents 5% of all CNS tumors in children.
What histologic grade is typical of OPG?
OPGs are typically low grade. Pilocytic astrocytoma (grade I) is the predominant histology. However, grade II has been reported.
What genetic syndrome is associated with OPG?
OPG is strongly associated with NF-1. Anywhere from 25% to 60% of pts with OPGs have NF-1. However, only 15%–20% of NF-1 pts have OPG (typically diagnosed before age 6 yrs), and only 1%–5% become symptomatic.
What are the subtypes of OPGs?
OPGs are organized by location:
Ant visual pathway (orbital, intracanalicular, and intracranial prechiasmal optic nerve)
Post visual pathway (chiasm, hypothalamus, ant 3rd ventricle)
Which OPG subtype is more common in children with NF-1?
Ant OPG is more common in children with NF-1, while post OPG is more common in NF-1 negative children.
Which subtype has the worst prognosis?
Post (esp hypothalamic) OPG has the worst prognosis (OS 50%–80%/LC 40%–60%) vs. other types (OS 90%–100%/LC 60%–90%).
How do pts with OPGs typically present?
Orbital tumors often present with painless proptosis. Other Sx include ↓ visual acuity, visual field defects, changes in appetite or sleep/precocious puberty (hypothalamic), and new-onset HA and n/v (obstructive hydrocephalus).
What is the typical clinical course of OPG?
The clinical behavior of OPG is variable in children, including spontaneous regression and malignant degeneration. OPGs are aggressive in adults, reflecting the commonly underlying malignant histology.
