Neurofibromatosis

• Neurofibromatosis, type 1 (NF1)
• Von Recklinghausen’s disease

• 237.70 Neurofibromatosis unspecified
• 237.71 Neurofibromatosis type 1 von Recklinghausen’s disease
• 237.72 Neurofibromatosis type 2 acoustic neurofibromatosis
• 237.73 Schwannomatosis
• 237.7 Neurofibromatosis
• 237.79 Other neurofibromatosis

• Q85.00 Neurofibromatosis, unspecified
• Q85.01 Neurofibromatosis, type 1
• Q85.02 Neurofibromatosis, type 2
• Q85.03 Schwannomatosis
• Q85.09 Other neurofibromatosis

• 5E: Impaired Motor Function and Sensory Integrity Associated with Progressive Disorders of the Central Nervous System

Description

• Group of neoplastic disorders resulting from an autosomal dominant genetic disorder or chromosomal mutation
• Type 1 is the most common with hyperpigmentation spots (café-au-lait spots) present at birth, tumors of skin, and progressive decline of nerves, muscle, and bones due to defect of chromosome 17
• Type 2, acoustic neuromas, due to defect of chromosome 22

Essentials of Diagnosis

• At least 2 of the following needed for diagnosis
  • At least 7 café-au-lait spots less than 5 mm prior to puberty and more than 15 mm after puberty
  • More than 2 neurofibromas
  • Optic glioma
  • More than 2 Lisch nodules (tumors on the iris)
  • Freckling in axilla or inguinal areas
  • Bony lesions
  • Immediate family member with type 1 neurofibromatosis
• Acoustic neuromas (type 2) involve tumors on inner ear nerves, brain, skull, spinal cord; including schwannomas, gliomas, and meningiomas

General Considerations

• Type 1 involves dermal and epidermal benign tumors that affect myelin (neurofibromas) of peripheral nerves that can erode bone or cause compression of the nerve including optic nerve gliomas
• Acoustic neuromas result in hearing and balance deficits, as well as difficulty swallowing, and problems with eye movements and speech

Demographics

• Neurofibromatosis type 1 accounts for 95% of all cases
• 1:3000 births2
• 50% risk in siblings3
• 40% of those affected develop complications3

Signs and Symptoms

• Café-au-lait spots (type 1)
• 62% seizures3
• 40% cognitive impairment3
• 15% hypertension3
• 15% optic glioma3
• Skin tumors
• Lisch nodules
• Large head
• Scoliosis
• Strabismus (crossed eyes)
• Amblyopia (lazy eye)
• Cranial nerve VIII tumors (type 2)
• Seizures
• Precocious puberty
• Difficulty with balance
• Tinnitus
• Vertigo
• Pain
• Numbness, tingling, weakness of toes or fingers
• Speech deficits
• Attention deficit hyperactivity disorder (ADHD)

Functional Implications

• Deafness
• Falls due to balance deficits
• Pain resulting in decreased function

Possible Contributing Cause

• Autosomal dominant genetic disorder or mutation of chromosome 17 (type 1) or chromosome 22 (type 2)

Differential Diagnoses2

• McCune-Albright syndrome
• Noonan syndrome
• LEOPARD syndrome
• Bannayan-Riley-Ruvalcaba syndrome (BRRS)

Laboratory Tests

• Genetic testing
• Amniocentesis
• Chorionic villus sampling

Imaging

• MRI
• X-ray
• PET scan
• CT scan

Medical Procedures

• Surgical removal ...