Neurofibromatosis (NF) is an autosomal dominant trait manifested by changes in the skin, nervous system, bones, and endocrine glands. These changes include a variety of congenital abnormalities, tumors, and hamartomas. Two major forms of NF are recognized:
- Classic von Recklinghausen’s NF, termed NF1 and first described in 1882;
- Central, or acoustic NF, termed NF2. Both types have cafe-au-lait macules and neurofibromas, but only NF2 has bilateral acoustic neuromas (unilateral acoustic neuromas are a variable feature of NF1). An important diagnostic sign present only in NF1 is pigmented hamartomas of the iris (Lisch nodules).
Causes of Neurofibromatosis
Action of an abnormal gene on cellular elements derived from the neural crest: melanocytes, Schwann cells, endoneurial fibroblasts.
Symptoms of Neurofibromatosis
- Multiple neurofibromas on the skin and under the skin, the sub-cutaneous lumps are characteristic of the disease and increase in number with age.
- Various other skin phenomena such as freckling of the groin and the arm pit.
- During adolescence, benign tumors may develop on the skin (cutaneous), under the skin (subcutaneous), and in connective nerve tissue (neurofibromas)
- Rubbery tumors of the skin called nodular neurofibromas.
Diagnosis
Two of the following criteria:
- Multiple CAL macules-more than six lesions with a diameter of 1.5 cm in adults and more than five lesions with a diameter of .5 cm or more in children younger than 5 years.
- Multiple freckles in the axillary and inguinal regions
- Based on clinical and histologic grounds, two or more neurofibromas of any type, or one plexiform neurofibroma
- Sphenoid wing dysplasia or congenital bowing or thinning of long bone cortex, with or without pseudoarthrosis
- Bilateral optic nerve gliomas
- Two or more Lisch nodules on slit-lamp examination
- First-degree relative (parent, sibling, or child) with NF1 by the preceding criteria
Treatment
An orthopedic physician should manage the two major bone problems: kyphoscoliosis and tibial bowing. A plastic surgeon can do reconstructive surgery on the facial asymmetry. The language disorders and learning disabilities should be evaluated by a psychologist. Close follow-up annually should be mandatory to detect sarcomas that may arise within plexiform neuromas. Surgical removal of pheochromocytoma.
Prevention
Neurofibromatosis cannot be prevented. People with a family history of the disease may choose to undergo genetic testing and counseling to determine if they are at risk for transmitting NF to their offspring.
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