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Case 3

12 y.o male with visual deficit.

4 y.o female

Neurofibromatosis-1 (von Recklinghausen’s disease)

Diagnosis requires at least 2 of the following:

Clinical

1st degree relative with NF-1

6 or more café-au-lait spots

2 or more Lisch nodules (hamartomas) of the iris

Intertriginous (axillary or inguinal; not exposed to sun) freckling

Radiologic

optic glioma (Bilateral considered pathognomonic.)

2 or more neurofibromas

1 or more plexiform neurofibromas

1 or more bone dysplasias

pseudarthrosis of a long bone

NF-1 vs. NF-2

Chromosome 17

<10 y.o.

1 in 4000 (3000-5000)

optic gliomas

bright (T2WI / FLAIR) lesions in cerebellum, brain stem (esp. pons), basal ganglia, and deep white matter

skin findings

Chromosome 22

10-30 y.o.

1 in 50,000

Vestibular schwannomas (bilateral)

Meningiomas

Ependymomas

“MISME”

Additional NF-1 features:

spinal cord Astrocytomas

skeletal dyslasias (including inferior rib notching & “ribbon ribs”)

sphenoid wing dysplasia

dural ectasia (with scalloping of the posterior vertebral bodies)

vascular stenoses (HTN in child sec. to renal artery stenosis)

Plexiform Neurofibromas (scalp, neck, mediastinum, retroperitoneum, CN-V, orbit) account for “elephantiasis”

MALIGNANT change

if lesion enhances or grows after adolescence

Pulmonary dz. in 20% (interstitial fibrosis, bullae)

NF-1 and Optic Gliomas

10-38% with optic gliomas have NF-1

15-40% with NF-1 have optic gliomas

Treatment withheld until patient is symptomatic secondary to slow-growing, low-grade nature.

Variable enhancement

Optic Glioma(s)

Optic Gliomas—Intracranial Extension (80-90%)

Neurofibroma--MR Signal

T1 WI

Low to intermediate signal

Collagen/fibrous tissue enhances

T2 WI: Heterogeneous

High

Myxoid tissue

Cystic degeneration

Low

Collagen

Fibrous tissue

NF-1

Lateral Thoracic Meningocele

Mediastinal Neurofibroma…”Bilateral apicoposterior masses are virtually diagnostic.” (Klein)

NF-1: Thoracic and Abdominal involvement