Malignant nerve sheath tumors are most likely to be caused by Schwann’s cells in the peripheral nerve sheath, and a few can be caused by malignant transformation of nerve sheath tumors or neurofibromas. The biological behavior is of low malignancy, which is often not easily diagnosed before surgery, and is prone to recurrence after surgery, especially metastasis by blood flow. Pathological features: the tumor is mostly round or ovoid with pseudo envelope and connective links with the nerve of origin, the tumor is hard in texture and grayish white in cut surface, microscopically the tumor is composed of epithelial cells and spindle cells and migrate with each other, the tumor cells are heterogeneous and can be divided into nests by thin fibers, in some areas the tumor cells can be seen around the thin-walled small blood vessels in pseudo chrysanthemum-shaped clusters. The tumor cells are abundant and arranged in fenestrations or swirls. The cells are well differentiated or poorly differentiated into pleomorphism, infiltrating the surrounding tissues, with nuclear schizophrenic images visible, showing low malignancy, 1-2 per field at high magnification. S-100 is a more sensitive and specific marker for malignant nerve sheath tumors. S-100 is a more sensitive and specific marker for malignant nerve sheath tumors, and its positive rate is reported to be over 70% at home and abroad. The main treatment method is surgery. Malignant nerve sheath tumor is not sensitive to radiotherapy and chemotherapy, and the prognosis is poor.