Grow without intervention (Sx, chemo or radiation)
Grow despite Intervention
Arrest without intervention 20%
Arrest after intervention
Regression and involution without intervention
Regression and involution after intervention
Dissemination or malignant degeneration
15% of NF1 patients
10% of all OPG are NF1-associated
Usually affects optic nerve and chiasm rather than hypothalamus
Precocious puberty
Tend to have better prognosis
Genotype–phenotype correlation in NF1
Mutation in the first third of the gene more likely to develop an optic pathway glioma
Sharif et al. J Med Genet. 2011 Apr
Chromosome 17
Lesion is believed to be of Benign Nature Lesion is believed to be of Benign Course & does not cause
complications No histo-patholgical diagnosis is required
Tumors involving exclusively the optic nerve (not progressing)
Tumors that obviously involve the optic chiasm or tracts (not progressing)
Tumors associated with NF1
After partial resection
Severe proptosis from large tumors
Decompression of large progressing tumorso To relief IC hypertension
o To relief hydrocephalus
o To relief pressure on surrounding structures
Optic pathway glioma in adults
Histo-pathologic diagnosis (optic glioma v/s other tumor)
Molecular genetic analysis
Y-H Chen and D H GutmannOncogene 33, 2019-2026 (17 April 2014)The molecular and cell biology of pediatric low-grade gliomas
BRAF fusion resulting from focal duplication at 7q34 (BRAF : KIAA1549 fusion)
o Infratentorial tumors > Suprantentorial tumors o The frequency of this change varies from 50 to 100%
BRAF V600E (point mutation): single amino acid changes (valine to glutamate change at position 600)o Suprantentorial tumors > Infratentorial tumors
Activation of the MAPK/ERK signaling pathway (mitogen-activated protein kinase/extracellular signal-regulated kinase) o identified in approximately 80–90% of PA
Pfister S et al. J Clin Invest 2008 May
Bar et al. J Neuropathol Exp Neurol. 2008 Sep
“Fusion-positive tumors” has favorable prognosis in 70 low grade astrocytoma
No association of “Fusion-positive tumors” with progression-free survival (poor prognosis in < 1 year age, incomplete resection in 93 PA cases)
Hawkins et al. Clin Cancer Res 2011
Cin et al. Acta Neuropathol. 2011
Upper nasal fibres
Macular fibres
Lower nasal fibres
Anterior clinoid
Pituitary gland
III rd ventricle
Craniopharyngioma
Optic chiasm
Diaphragma sellae
Posterior clinoid
Dorsum sellae
Visual field defects in Pituitary Adenomas
LE RE
HM
CF
AnteriorlyDecussating fibresare most vunerable
Meningioma
LE RE
Junctional scotoma
Tuberculum Sellameningioma
Olfactory groove meningioma
Sphenoid ridge meningioma
Ophthalmic ArterySup. Hypophysial Artery
Ant. Cer. Arteries & A. Com. ArteryP.Com. Artery
Blood Supply of the Optic Chiasm