Surgical treatment Parotid malignant tumors are mainly treated by surgery, and the scope of surgical resection should be decided according to the size of the lesion, pathological type and degree of malignancy. Surgical methods: there are 2 methods: from front to back, separating the parotid duct first and from back to front, dissecting the trunk of facial nerve first. The former method is suitable for mixed tumors located under the ear, and the latter method is suitable for mixed tumors in the anterior part of the parotid gland. (1) Due to the incomplete tumor envelope and infiltrative growth, it is often difficult to determine its boundary, so the normal tissue should be widely resected for the first time when the surgery is performed more than 1cm away from the tumor, which is an important measure to improve the long-term therapeutic effect. If the resection is incomplete and thorough, it is easy to recur, and although surgery is performed again, it often fails to obtain satisfactory results. (2) Do not cut through the tumor peritoneum during surgery, otherwise the tumor tissue will spill out, which will easily cause implantation recurrence. (3) If frozen section examination is needed during surgery, it should be done after complete resection of the tumor, and then the tissue should be cut and sent for examination. Attention should be paid to the presence or absence of cancer cells in the border tissues to determine whether the resection area is completely and thoroughly clean. (4) When separating the facial nerve, it should be separated step by step along its direction on the superficial side, avoiding separation on the deep side, and do not injure the sheath membrane of the facial nerve. (5) In case of bleeding, saline gauze should be used to stop bleeding by pressing or gently wiping the blood, and friction and clamping to stop bleeding are strictly prohibited. (6) When the facial nerve is involved in the operation, it should be determined according to the relationship between the tumor and the facial nerve, and the risk of recurrence should not be taken simply for the sake of preserving the facial nerve, but it should be estimated according to the clinical manifestations before the operation, so as to facilitate the operation. (7) After partial resection of the facial nerve, an end-to-end anastomosis of the facial nerve or an anastomosis between the proximal part of the parasympathetic nerve and the peripheral part of the facial nerve can be performed under tension-free conditions as appropriate. For larger defects, auricular nerve or peroneal nerve graft can be applied. If the facial nerve is removed, the deformity can be improved and function restored with fascial suspension or bite muscle transfer, as well as suture of the inner and outer canthus of the eye. (8) For low-grade malignant tumors, such as highly differentiated mucoepidermoid carcinoma, as long as there is a certain distance from the facial nerve, or the facial nerve is mildly adherent to the tumor but can still be separated from it, it should be separated and preserved as much as possible. Intraoperative liquid nitrogen freezing should be used to treat the facial nerve and its surrounding tissues, or postoperative radiotherapy should be given. (9) There are different opinions on whether cervical lymph nodes should be subjected to cervical lymph node dissection. Some think that except for highly differentiated mucoepidermoid carcinoma, cervical lymph node dissection should be performed even if there are no enlarged lymph nodes. Some think that cervical lymph node dissection should be performed even if there is no enlarged lymph nodes. Some think that cervical lymph node dissection is only applicable to those with palpable enlarged lymph nodes and suspected metastasis. However, for highly malignant parotid adenocarcinoma (squamous carcinoma, undifferentiated carcinoma, poorly differentiated carcinoma, mucoepidermoid carcinoma), which has a high metastatic rate, selective cervical lymph node dissection can be performed. (10) If there is adhesion between the mandible and the tumor, there is no bone destruction in imaging diagnosis. Local resection of jawbone is feasible; if there is destruction, it should be resected together with the tumor. Radiotherapy Radiotherapy is only one of the comprehensive treatments. In order to reduce postoperative recurrence, radiotherapy can be supplemented for those with highly malignant pathology or those whose surgery is not thorough enough, those who are suspected to have residual tumor tissues, those whose facial nerve is tightly adhered to the tumor and retained, and those with late stage of the disease, which can significantly improve the survival rate and reduce the recurrence rate after the surgery. Postoperative radiotherapy should be started as early as possible, not later than 6 weeks after surgery. The irradiation field includes skull base and mastoid process, and the dose should be 50-60Gy. Chemotherapy The chemotherapy of parotid malignant tumor is unlike that of malignant lymphoma and squamous cell carcinoma, which has a systematic and standardized treatment plan. Effective drugs include cisplatin, methotrexate, fluorouracil (5-FU), and doxorubicin (adriamycin). Chemotherapy is not effective in parotid tumors and is only used as one of the means of comprehensive adjuvant therapy. Parotid gland epithelial malignant tumors, except undifferentiated carcinoma, squamous carcinoma and adenocarcinoma, other less malignant carcinomas can often obtain certain effect after appropriate treatment.