Phakomatosis - NF1

Question 1

Most common phakomatosis

Answer 1

NF1

Question 2

NF1 chromosome

Answer 2

chromosome 17

17q11.2; tumor suppressor of Ras/MAPK pathway is broken

Question 3

another name for NF1

Answer 3

von Recklinghausen

Question 4

• Nerve stuff
  
  • plexiform neurofibroma
  • optic nerve glioma
  • eye hamartomas (lisch nodules)
• skin stuff
  
  • > 6 cafe au lait spots in one year
  • intertriginous freckles
• bone stuff
  
  • sphenoid wing dysplasia
  • pseudoarthrosis

Answer 4

NF1

Question 5

Answer 5

pseudoarthrosis

NF1

Question 6

Answer 6

NF1

progressive bowing fo the anterolateral tibia and

pseudoarthrosis of the fibula (cupping of the bone proximal to the absent section and sharpened narrow appearance of the distal bone)

Question 7

Answer 7

NF1

pseudoarhtrosis

Question 8

in a patient with NF1, where do Juvenile pilocytic astrocytomas occur?

Answer 8

optic pathway

***JPAs in the posterior fossa are NOT associated with NF1

Question 9

inheritance pattern of NF1

Answer 9

50% AD

50% spontaneous mutation

Question 10

Answer 10

NF1 cutaneous nodules

Question 11

Answer 11

NF1 mammo

multiple cutaneous neurofibromas outlines by air

Question 12

Answer 12

NF1 sphenoid wing dysplasia

Sphenoid wing dysplasia is seen in 5-10% of cases of NF1 and is one of the diagnostic criteria of NF1

Question 13

Answer 13

NF1

“bare orbit sign” in the right orbit. Sphenoid bone dysplasia allowing the frontal lobe to herniate.

Arrow on the prior image pointed to a normal left lesser sphenoid wing

https://radiopaedia.org/cases/bare-right-orbit-sphenoid-dysplasia-due-to-neurofibromatosis-type-1?lang=us

Question 14

Answer 14

NF1 - sphenoid bone dysplasia

https://radiopaedia.org/cases/sphenoid-wing-dysplasia

Question 15

Answer 15

unidentified bright object - NF1

Question 16

cause of Focal areas of signal intensity (FASI) in NF1 patients

(previously called “unidentified bright objects”)

Answer 16

thought to be caused by spongiform myelinopathy/ myelin vacuolization

no inflammation and NO demyelination

Question 17

In NF1 patients which FASI is associated with cognitive impairment?

Answer 17

thalamic FASIs

Question 18

NF1 patient

Answer 18

FASI

Question 19

FASI lesion seen in what age?

Answer 19

4-12 year old –> fades over time into adulthood

Question 20

WHO grade of neurofibromas

Answer 20

WHO grade 1

Question 21

plexiform neurofibroma risk of malignant degeneration

Answer 21

5%

Question 22

Answer 22

peripheral nerve sheath tumor - target sign

most commonly associated with a localized neurofibroma

Question 23

optic nerve glioma association

Answer 23

NF1

Question 24

Answer 24

acute cervical kyphosis in a pt with NF1 and multiple plexiform neurofibromas

Question 25

Answer 25

Cervical spine neurofibroma --\> cervical kyphosis [https://radiopaedia.org/cases/cervical-spinal-neurofibroma-in-a-patient-with-nf1](https://radiopaedia.org/cases/cervical-spinal-neurofibroma-in-a-patient-with-nf1)

Question 26

Answer 26

Question 27

Answer 27

NF1 ribbon ribs (on the right) and multiple cutaneous nodules (yellow arrows) [https://radiopaedia.org/cases/neurofibromatosis-type-1-ribbon-ribs-2?lang=us](https://radiopaedia.org/cases/neurofibromatosis-type-1-ribbon-ribs-2?lang=us)

Question 28

Answer 28

NF1 vertebral body scalloping There are exaggerated concavities of almost all of the lumbar vertebral bodies posteriorly (red arrows) in a patient with neurofibromatosis. The scalloping may be due to dural ectasia (more commonly) or neurofibromas themselves.

Question 29

Answer 29

NF1 dural ectasia

Question 30

NF1 extracranial neoplasms

Answer 30

* Wilms * Rhabdomyosarcoma * AML * leiomyosarcoma

Question 31

renal artery stenosis in a teenager

Answer 31

NF1

Question 32

teenageer with HTN

Answer 32

NF1

Question 33

Answer 33

Bupthalmos =enlarged eyeball due to increased intraocular pressure from sphenoid dysplasia (absent orbit) this NF1 or sturge weber

Question 34

Answer 34

NF1 plexiform neurofibromas in the sacrum

Question 35

Answer 35

NF1 widened neuroforamen

Question 36

Answer 36

NF1 plexiform neurofibromas

Question 37

difference between a Schwannoma and a neurofibroma

Answer 37

Neurofibromas infiltrate the nerve - resection requires nerve sacrifice Schwannoma is ECCENTRIC to the nerve - can be scooped out with sparing the nerve

Question 38

Answer 38

NF1 lateral thoracic meningocele

Question 39

Answer 39

NF1. CT lateral thoracic meningocele results from herniation of the meninges through a foramen or a defect in the vertebral column. They are typically associated with neurofibromatosis type I but can rarely occur in isolation. In these patients, they may occur in association with thoracic spine scoliosis. **When scoliosis/kyphosis is present, the meningocele is located at the apex of the convexity.**

Question 40

vascular anomalies in NF1

Answer 40

* aortic coarctation * renal artery stenosis * aneurysms * AV fistula

Question 41

Answer 41

NF1 optic nerve glioma

Question 42

10 yokid with blurred vision, cafe au lait spots

Answer 42

NF1 with FASI in basal ganglia and bilateral optic nerve gliomas