Malignant nerve sheath tumor Malignant nerve sheath tumor, also known as neurofibrosarcoma, is a neuroectodermal abnormality caused by aberrant dominant genes, resulting in multiple tumor-like proliferation of peripheral nerves and connective tissue proliferation in the nerve sheath and nerve fibers. There is a family history of approximately 25 to 30. Hypodifferentiated spindle cell sarcomas originating from peripheral nerves occur mostly in adults and the elderly. The trunk is the preferred site, followed by deep soft tissues, retroperitoneum and mediastinum. The tumor grows suddenly and rapidly, often with a pseudophakic envelope of more than 5 cm: it can be divided into 6 types: 1. malignant salamander tumor: the malignancy is higher, and heterologous components such as bone, cartilage and adipose tissue are common in the tumor. 2, malignant salamander tumor: the tumor is accompanied by a higher amount of rhabdomyosarcoma components, and the rhabdomyosarcoma cells have typical rhabdomyosarcoma differentiation. 3.Malignant melanotic Chewannoma: There is melanin distributed in the tumor, scattered or all over the tumor. 4.Malignant epithelioid Chewang tumor: epithelioid or adenoid cell differentiation appears in the tumor. 5. Malignant glandular Chewang tumor: glandular-like structures appear in the tumor, and mucus-secreting cup-like cells may appear in the glandular epithelium. 6.Malignant clear cell sarcoma: It is a clear cell sarcoma differentiated by sarcoma cells. This tumor mostly occurs in young and middle-aged males, and it usually occurs in the limbs or scalp and neck. The tumor grows slowly, usually over 5 years, and is often accompanied by neurofibroma or nerve sheath tumor. About 2/3 of the cases are based on recurrent malignant changes of these two diseases. The tumor is composed of malignant nerve sheath cells and nerve membrane cells, and the envelope is often incomplete, mostly infiltrated by tumor cells. The tumor cells are spindle-shaped, infiltrative, and arranged in interwoven cords, sometimes feathery, or occasionally fenestrated or reticulated structures with foci of hemorrhage and necrosis. The nuclei of the tumor cells are ovoid or spindle-shaped, some are polygonal, vary in size, and have distinct heterotypes. The nuclear mitotic signs are common. Fibrosarcoma, often without envelope, has less bleeding and necrosis. The nuclei of tumor cells are slightly pointed at both ends, and there are more collagen fibers in the cytoplasm and interstitium. 2. Smooth muscle sarcoma, which contains myogenic fibers in the tumor cells, stains purple-blue for PTAH and red for trichrome staining. The difference between nerve sheath tumors and neurofibromas 1. nerve sheath tumors have an intact envelope, while neurofibromas do not have an envelope; 2. nerve sheath tumors are composed of Schwann cells, while neurofibromas are composed of Schwann cells, nerve bundle cells, and fibroblasts; 3. nerve sheath tumors have an A.B area, and the vessel walls are often glassy, while neurofibromas have more obvious mucous changes, and the spindle-shaped tumor cells are arranged in waves with The nerve sheath tumor has A.B area, the blood vessel wall is often glassy, and the mucinous change of neurofibroma is more obvious, and the spindle-shaped tumor cells are arranged in waves with “carrot” fragment-like collagen fibers, which are often closely related to the nerve. Excision should be expanded to avoid recurrence