Table of Contents Suggested approach to neurofibromatosis type 1 osce stationDescribing lesionsIf you are allowed to ask the patient questionsDifferential diagnosisTypes of neurofibromatosis Type 1 (peripheral) Type 2 (central)Here are some questionsTry a station Neurofibromatosis is an autosomal dominant condition resulting in the growth of nerve tumours Suggested approach to neurofibromatosis type 1 osce station Describing lesions Neurofibromas‘There are multiple, well-demarcated brown circular nodules and papules present across the back in a generalized distribution.’ ‘There are no secondary features (such as crusting, scaling or erosion).’‘On palpation, these lesions are soft and non-tender, with some exhibiting the button-hole sign.’‘These lesions are consistent with neurofibromas.’Café au lait spots‘There are also irregularly shaped, evenly pigmented, flat brown patches.’‘These are characteristic of café au lait spots.’Other areas‘I would like to look for axillary and inguinal freckling, and abdominal scars (e.g. for phaeochromocytoma surgery).’Conclusion‘Given there are 2 or more neurofibromas and 6 or more café au lait spots, the likely diagnosis is neurofibromatosis type 1.’‘In addition to examining the rest of the skin and taking a full history, I would like to measure blood pressure, do a full neurological exam for signs of spinal cord neurofibromas, examine the eyes for signs of optic nerve gliomas, and use a slit lamp to look for Lisch nodules on the iris.’ NeurofibromasNeurofibromatosis If you are allowed to ask the patient questions Family historyEyes, ears, blood pressureAny nerve lesions Differential diagnosis Neurofibromatosis type 2Tuberous sclerosis (multi-system hamartoma formation) Types of neurofibromatosis Type 1 (peripheral) NF-1 gene defect (chromosome 17) resulting in peripheral neurofibromas (i.e. in skin or subcutaneous tissue)SkinNeurofibromas (2 or more): well-demarcated nodules which are erythematous and varied in size and shape Café au lait spots (6 or more): flat patch of asymmetrical darkened skin (brown/black)Axillary frecklingOther featuresOptic nerve glioma → non-correctable visual lossLisch nodules (iris hamartomas, i.e. brown spots on iris seen with slit lamp)Dorsal root spinal cord tumoursPlexiform neurofibromas (diffuse and invasive → bony erosion) Type 2 (central) Merlin protein gene defect (chromosome 22) resulting in central schwannomasMost common presenting condition is bilateral acoustic neuromas (CN8) causing hearing loss, typically at 20-30 years of ageOther conditions include: meningiomas, gliomas, juvenile cataractsOther symptoms include: headache, balance loss, vertigo, facial weakness, deafness, tinnitusSkin symptoms uncommon Here are some questions How is neurofibromatosis diagnosed? Oops! This section is restricted to members. How is neurofibromatosis managed? Oops! This section is restricted to members. Try a station Dermatological skin examNeurofibromatosis examLots more here