Neurofibromatosis
type 1 (NF1)
Epidemiology and
Etiology:
- Autosomal
dominant
- high
penetrance, early on (childhood)
- NF-1 gene (17q11.2)
- Encodes
neurofibromin protein
- Inner
aspect of plasma membrane
- Downregulates p21Ras (cell
cycle inhibitor) resulting in:
- Lack
of inhibition of cell cycle
- Increases
RAS signal transduction
Common sites:
- Peripheral
nerve and skin:
- neurofibromas
- café au lait patches
- axillary
/ groin freckling
- MPNST
- CNS :
- Gliomas
(optic nerve, brain stem)
- meningiomas
- Eye:
- Lisch nodules (pigmented hamartomas)(94% of patients > 6y)
- Adrenal
and ANS:
- Bone
(30-50%)
- Scoliosis
- Intraosseous cystic lesions
- Subperiosteal bone cysts
- Bony
dysplasia
- Pseudoarthrosis of tibia/fibula
- Sphenoid
wing dysplasia
- Lamboid
suture defects
- GI:
- GIST
(5-25%) (small intestine > stomach)
- Ganglioneuromatosis
- Kidney:
- Soft
tissue:
- Bone
marrow:
- Skin:
Gross features:
Histologic features:
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- Reduced
intelligence often
- Intestinal
obstruction (mass effect)
- Hypertension
(renal artery mass effect)
References:
- WHO
Tumours of Endocrine Organs (2004)