Most tumors (benign and malignant) do not arise from the nerves per se, but from the supporting cells; tumors arising from the cells of Schwann are termed schwannoma or neurilemoma--benign or malignant. Surgical extirpation is the only way of treating these tumors. Radiation therapy can offer significant palliation and prolongation of life, but no cures have been observed. Other forms of therapy (chemotherapy, immunotherapy, etc.) have little to offer at this time. Benign tumors can be treated by local surgical extirpation; malignant tumors must be radically resected, including major amputations where indicated. Certain dermatomes have a proclivity to produce tumors, and new growths (benign and malignant) proximal to the one clinically apparent can be expected in certain patients. Neurofibromatosis (von Recklinghausen's disease) is a genetic error of metabolism with a proclivity to produce multiple neurofibrosarcomas, and in about 10 percent of the patients, malignant neurilemomas. Of 100 patients with malignant neurilemomas treated by the author, 74 were considered determinate; among them, the 10-year "cure" rate was 32 percent. Patients with von Recklinghausen's disease had almost as good a 10-year survival rate as those with solitary malignant schwannoma (30 percent vs 39 percent).