Chapter 27: Peripheral Nerve Sheath Tumors Flashcards
What are the major manifestations of Tuberous Sclerosis?
- autosomal dominant
Seizures, autism, and mental retardation
- Hamartomas: cortical tubers
- Renal angiomyoplipomas
- Cardiac rhabdomyomas
- Shagreen patches and Ash-leaf patches
-“candle guttering”: drop-like masses bulge into the ventricles
What genes are associated with Tuberous sclerosis complex?
What chromosome are they on?
What protein do they encode for?
- TSC1, Chromosome 9q34, hamartin
- TSC2, Chromosome 16p13.3, tuberin
Which hematologic complication may be seen with Von Hippel-Lindau disease?
Polycythemia
What chromosome is the NF1 gene located on?
17q11.2 (tumor suppressor neurofibromin)
What does NF1 lead to?
neurofibromas of peripheral nerves
optic nerve gliomas
Lisch nodules
Cafe au lait spots
What chromosome is the NF2 gene on and what is the gene product?
chromosome 22q12
merlin
What is NF2 associated with?
bilaterally schwannomas (CN VIII), multiple meningiomas, ependymomas of spinal cord
What is characteristic histology of Schwannoma’s?
- Antoni A areas: spindle cells, Verocay bodies = palisading nuclei around “nuclear free zones”
- Antoni B: hypocellular, myxoid extracellular matrix
Where do Schwannomas arise within cranial vault and what are the signs/sx’s?
- Arise cerebellar pontine angle; attached to vestibular branch of CN VIII
- Pt’s present with tinnitus and hearing loss - acoustic neuroma
Which gene mutation is a consistent finding in all Schwannomas?
Inactivation of NF2 on Cr. 22 –> loss of Merlin expression
Which pattern of Neurofibromas grows within and expands nerve fascicles, entrapping associated axons and is sometimes describes as a “bag of worms?”
Plexiform neurofibromas
Which growth pattern of neurofibromas may transform to a malignant peripheral nerve sheath tumor?
Plexiform neurofibroma
What is the grade of most malignant peripheral nerve sheath tumors (MPNST) and half arise in which patients?
- 85% are high grade
- Half arise in NF1 pt’s: malignant transformation of plexiform subtype
Malignant peripheral nerve sheath tumors (MPNST) that has focal areas exhibiting rhabdomyoblastic morphology are termed what?
Triton tumors
What are the manifestations of Neurofibromatosis type I?
- Neurofibromas of peripheral nerves
- Optic nerve gliomas
- Lisch nodules: pigmented nodules of the iris
- Café-au-lait spots
What are the common manifestations of Neurofibromastosis type 2?
- Bilateral scwannomas (CN VIII), cerebellopontine angle
- Multiple meningiomas and ependymomas of the spinal cord
The NF2 gene is located on which chromosome and what is it’s normal gene product?
NF2 on Cr. 22 –> Merlin (tumor suppressor)
