Neurofibromatosis Type I (NF-1) or von Recklinghausen disease is an autosomal dominant disorder localized to a mutation on chromosome 17. It presents with a wide variety of clinical manifestations.
Diagosis may be made when a patient presents with two or more of the following:
1. Six or more cafe au lait spots
2. Two or more neurofibromas of any type or one plexiform neurofibroma
3. Axillary or inguinal freckling
4. Optic glioma
5. Two or more iris hamartomas (Lisch nodules)
6. Distinctive osseous lesion (sphenoid dysplasia or long bone cortical thinning)
7. A first-degree relative with NF-1.

The clinical manifestations may vary between patients. Some may experience no mental difficulties with significant musculoskeletal and peripheral nervous problems, while others may have learning disabilities. Other potential problems associated with the disease include, but are not limited to, renal artery stenosis, astrocytomas, scoliosis, dural ectasia with posterior vertebral scalloping, and lateral thoracic meningoceles.

The paraspinous neurofibromas seen in NF-1 are typically ovoid when small. They may be entirely within the spinal canal, but as they grow, may extend into, and widen neural foramina. Plexiform neurofibromas tend to be locally agressive and infiltrate along the nerve of origin. They can invade surrounding structures and cause local destruction.