Neurofibromatosis Flashcards
What is neurofibromatosis?
It is defined as an inherited condition, in which neuromas develop throughout the nervous system
What are neuromas?
They are defined as nerve tumours
What is the inheritance of neurofibromatosis?
Autosomal dominant
Are the neuromas associated with neurofibromatosis benign or malignant?
Benign
What are the two classifications of neurofibromatosis?
Neurofibromatosis type I
Neurofibromatosis type II
What is the most common neurofibromatosis classification?
Neurofibromatosis type I
What is another term for neurofibromatosis type I?
Von Recklinghausen’s syndrome
What genetic mutation causes neurofibromatosis type I? What chromosome is this gene located on?
Neurofibromin gene
Chromosome 17
What is neurofibromin?
A tumour suppressor protein
What is neurofibromatosis type I?
It is a condition in which there is development of neoplastic lesions in the pituitary gland, parathyroid gland and pancreas
What are the ten clinical features associated with neurofibromatosis type I?
Café-Au-Lait Spots
Axillary/Groin Freckles
Bony Dysplasia
Iris Hamartomas
Neurofibromas
Glioma of Optic Nerve
Scoliosis
Phaeochromocytoma
Peptic Ulceration
Galactorrhoea
What are cafe-au-lait spots?
They are defined as flat light brown patches of skin
What two forms of bony dysplasia are associated with neurofibromatosis type I?
Long bone bowing
Sphenoid wing dysplasia
What are iris hamartomas?
They are defined as yellow brown spots located on the iris
What type of iris hamartomas are most commonly associated with neurofibromatosis type I?
Lisch nodules
How do we diagnose neurofibromatosis type I?
Clinically
No investigations are required to obtain a definitive diagnosis
What electrolyte imbalance is associated with neurofibromatosis type I?
Hypercalcaemia
What are the clinical criteria required to obtain a diagnosis of neurofibromatosis type I?
A diagnosis of neurofibromatosis can be obtained in cases where two of the following criteria are met…
Café-Au-Lait Spots > 6 (> 5mm In Children OR > 15mm In Adults)
Relative With Neurofibromatosis Type I
Bony Dysplasia
Iris Hamartomas > 2
Neurofibromas > 2
Glioma of Optic Nerve
How do we manage neurofibromatosis type I?
It involves providing symptomatic control, monitoring disease progression and complication treatment
There is no management options available to treat the underlying disease process or slow down the progression of disease
What are the ten complications associated with neurofibromatosis type I?
Malignant Peripheral Nerve Sheath Tumours
Brain Tumours
Spinal Cord Tumours
Spine Scoliosis
Migraines
Epilepsy
Vision Loss
Gastrointestinal Stromal Tumour
Renal Artery Stenosis
Leukaemia
What is Zollinger-Ellison syndrome?
It is a condition in which there is increased levels of gastricn, usually from a gastrin secreting tumour of the duodenum or pancreas
What neurofibromatosis classification is Zollinger-Ellison syndrome associated with?
Neurofibromatosis type I
What are the three clinical features of Zollinger-Ellison syndrome?
Duodenal ulceration
Diarrhoea
Malabsorption
What are the two investigations used to diagnose Zollinger-Ellison syndrome?
Fasting gastrin blood test
Secretin stimulation test
What genetic mutation causes neurofibromatosis type II? What chromosome is this gene located on?
Merlin gene
Chromosome 22
What is merlin?
A tumour suppressor protein, which is particularly important in Schwann cells
What neuroma type is associated with neurofibromatosis type II?
Bilateral vestibular schwannomas
What is another term for vestibular schwannomas?
Acoustic neuromas
What is a vestibular schwannoma?
A tumour of the auditory nerve innervating the inner ear
What are the three clinical features of neurofibromatosis type II?
Hearing Loss
Tinnitus
Balance Problems
How do we manage neurofibromatosis type II?
It involves surgical resection of the vestibular schwannomas
What is a risk of vestibular schwannoma resection?
Permanent auditory nerve damage
What are the two complications associated with neurofibromatosis type II?
Brain Tumours
Spinal Cord Tumours
