malignant peripheral nerve sheath tumour(redirected from MPNST)
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malignant peripheral nerve sheath tumourA poorly understood malignancy, presumably of Schwann cell origin, which is thought to arise from the neural crest. It is the most common malignancy of peripheral nerves, and represents 5 to 10% of all soft-tissue tumours. It occurs in the lower extremities in relatively young patients (age 20 to 50). Half of cases occur in patients with neurofibromatosis type 1, in which the male:female ratio is 4:1; 2/3 of MPNSTs arise from neurofibromas, 1/3 arise de novo. Origin from pre-existing schwannomas, ganglioneuromas or phaeochromocytomas are rare; 10% arise in a background of therapeutic radiation.
Wide local excision; radiation and chemotherapy have been used with varying degrees of failure.