Astrocytomas occur principally in the cerebral and cerebellar hemispheres and the brain stem. Nerve Sheath Tumors Malignant peripheral nerve sheath tumors includes neurofibrosarcomas and malignant schwannomas. Despite this low absolute risk, the relative risk to persons with neurofibromatosis type 1 is much higher because the frequency in the general population is so low. Patients should be strongly advised to report sudden enlargements or painful growths. Peripheral nerve malignancies either arise de novo or through malignant change in an existing plexiform neurofibroma.
Cutaneous neurofibromas appear to lack the propensity to become malignant.
These tumors arise in the pelvis and present between 7 and 13 months of age in patients with neurofibromatosis type 1. Endocrine tumors Pheochromocytoma and duodenal carcinoid are tumors associated with neurofibromatosis type 1. There are no specific treatments for neurofibromatosis type 1 or drug therapies that can prevent or treat the growth of neurofibromas. The variable nature and severity of neurofibromatosis require coordination of medical care. Many persons affected with neurofibromatosis will not develop major complications.