NF1 Flashcards
CAFE SPOT
C: café-au-lait spots (greater than six seen during one year)
A: axillary or inguinal freckling
F: fibromas (neurofibroma (two or more) or plexiform neurofibroma (one))
E: eye hamartomas (Lisch nodules)
S: skeletal abnormalities, e.g. sphenoid wing dysplasia, leg bowing
P: positive family history
OT: optic tumor (optic nerve glioma)
Epidemiology of NF1
1:2500-3000 individuals
50% autosomal-dominant, 50% de novo
variable expression
100% penetrance by the age of 5
renal artery stenosis in NF1
1%
learning disability
45%
types of neurofibromas in NF1
localized neurofibroma (cutaneous neurofibroma): the most common type, is a focal lesion that typically is located in the dermis and subcutis
diffuse neurofibroma (subcutaneous neurofibroma): localized in the subcutis, usually in the head and neck region
plexiform neurofibroma: considered pathognomonic if present; they may be seen in virtually any location but usually occur in the neck, pelvis, and extremities
pathology of NF1
17q11.2
neurofibromin tumor suppressor of the Ras/MAPK pathway
RASopathy
hamartomous disease - right cells in wrong artchitecture
CNS manifestation of NF1
FASI (focal areas of signal intensity): occur in deep white matter and basal ganglia or corpus callosum 5, areas of T2/FLAIR hyperintensity with no contrast enhancement
optic nerve glioma or optic pathway glioma (may manifest as enlarged optic foramen)
progressive sphenoid wing dysplasia
J-shaped sella
lambdoid suture defects
dural calcification at the vertex
moyamoya phenomenon (rare)
buphthalmos
FASI pathology
spongiform myelinopathy or vacuolar change of myelin with no inflammatory reaction in the surrounding tissue and no frank demyelination
causes of hydrocephalus in NF1 children
OPGs, other CNS tumors, NF changes with a
mass effect compressing the CSF pathways, and aqueductal
stenosis
periaqueductal gliosis, NF tissue changes
