70 Neurofibromatosis
Salient features
History
• Presents in childhood with cutaneous features including café-au-lait spots, axillary freckles and neurofibromas
• Obtain history of learning disabilities (about half the patients with neurofibroma 1 are affected; Nature 2000;403:846–7)
• Childhood leukaemia: the risk of malignant myeloid disorders, particularly juvenile myelomonocytic leukaemia and the monosomy 7 syndrome (a childhood variant of myeloid dysplasia) is 200 to 500 times the normal risk (N Engl J Med 1997;336:1713–20).
Examination
• Multiple neurofibroma and café-au-lait spots (brown macules, >2.5 cm diameter and >5 lesions)
• Examine the axilla for freckles
• Check visual acuity and fundus for optic glioma (Fig. 70.1)
• Hearing and corneal sensation for acoustic neuroma
• The iris for Lisch nodules (often apparent only by slit-lamp examination). The incidence of Lisch nodules in type 1 increases with age (at the age of 5 years only 22% have Lisch nodules, whereas at the age of 20 years 100% have them). Therefore, older individuals who do not have Lisch nodules are unlikely to have type 1 neurofibromatosis (Fig. 70.2)
• The spine for kyphoscoliosis
• Tell the examiner that you would like to check the BP (for renal artery stenosis or phaeochromocytoma).
