Pediatric Radiology > Neurological > Neurocutaneous Syndromes > Neurofibromatosis


Neurofibromatosis

The most common phakomatoses are divided into a number of subcategories, of which neurofibromatosis 1 (NF1) and 2 (NF2) are the most common. NF1 is an autosomal dominant disorder. The diagnostic criteria for NF1 include two or more of the following:

  1. Six or more cafe-au-lait macules
  2. Two or more neurofibromas or one plexiform neurofibroma
  3. Axillary or inguinal freckles
  4. Bilateral optic nerve gliomas
  5. Two hamartomas of the iris (Lisch nodules)
  6. Parent, sibling, or child with NF1
The most common CNS lesions are the NF1 spots that are high signal intensity lesions in the globus pallidus, cerebellum, brainstem, internal capsule, splenium, and thalami. The lesions arise at 3 years and typically regress after 12.

   

The pictures below show where the lesions are in the above MRI images.
   
In contrast, NF2 patients present typically in adulthood, characterized by bilateral acoustic schwannomas. Other lesions include meningiomas, gliomas, and neurofibromas.
   
NF2 with bilateral VIII schwannomas, right optic nerve meningioma, and posterior meningioma.