1, tonsils and their functions in the human oropharynx there is a ring-shaped distribution of lymphatic tissue, called the pharyngeal lymphatic ring or called Waldeyer’s ring (Waldeyer’s ring), which is a defense barrier in the human body, at the entrance to the respiratory and digestive tracts, to prevent the invasion of germs, so called the first line of defense, including the nasopharynx, the lateral and posterior walls of the oropharynx, tonsils, soft palate and tongue root. The tonsils are the largest lymphatic tissue and are located in the tonsillar fossa of the lateral wall of the pharynx. The normal tonsils, in addition to directly preventing bacterial invasion, are one of the sites for the production of human immunoglobulins, which are involved in the immune function of the body, and are rich in immune substances, which have sufficient capacity to engulf and kill harmful substances. Because of its participation in the immune function of human body, it has been found that some immune disorders, allergic diseases or certain tumors are related to the functional status of tonsils. Tonsil cancer is the most common malignant tumor in the oropharynx, accounting for about half of the cases. The cause of its development is not very clear, but heavy smoking and excessive alcohol consumption are thought to be closely related to the occurrence of tonsil cancer. In addition, it has been reported in the literature that people with autosomal recessive genetic syndrome are prone to this disease. Tonsil cancer is commonly found in lymph node metastasis in the deep upper neck of the affected side, and bilateral lymph node metastasis in the neck may also occur. Abnormal manifestations (1) The early symptoms of tonsil cancer are often mild, such as discomfort in the throat, foreign body sensation, slight pain in the throat, and small nodular elevation or ulcer in the tonsils. (2) With the development of the disease, pharyngeal swelling, pharyngeal obstruction, swallowing difficulty, pharyngeal pain, oral malodor due to tumor ulceration and necrosis, etc. will appear. (3) In advanced stage, the tumor invades into the surrounding tissues, there may be difficulty in opening the mouth, tongue movement, tinnitus and deafness due to invasion of nasopharynx, enlarged lymph nodes in the neck, and weight loss, etc. (4) Squamous epithelial cell carcinoma is the most common pathological type, accounting for about 50%, followed by low differentiated carcinoma and a few adenocarcinomas. 4.Related examinations (1) General physical examination: carefully examine the shape, size and invasion of adjacent structures of the primary tumor. Palpation is necessary to understand the hardness of the tumor, the extent and depth of the actual invasion, and whether the lymph nodes in the neck are enlarged, etc. (2) With the help of nasopharyngoscope and laryngoscope, to understand whether there is tumor invasion in the nasopharynx, hypopharynx and other parts that cannot be touched by fingers or visualized. (3) Imaging examination: taking lateral X-ray of nasopharynx, oropharynx and hypopharynx, CT scan and/or MRI can understand the infiltration of tumor to the surrounding and deeper parts, which is helpful to determine the stage and formulate the treatment plan. (4) Take tumor tissue specimens for pathological examination to clarify the nature and pathological type of tumor. 5.Treatment of tonsil cancer is mostly poorly differentiated squamous carcinoma or undifferentiated carcinoma, so it is more sensitive to radiotherapy. In addition, because the primary tumor has the characteristics of fast development, easy to invade adjacent tissues such as tongue root, soft palate or oral cavity of oropharynx, and easy to have early lymph node metastasis, it is difficult to perform extensive radical resection in surgery, and the surgery is more destructive and has many complications, so radiotherapy is mostly preferred. For a few well-differentiated tumors with small tumors limited to tonsillar fossa, surgery or radiotherapy + surgery can be considered as a comprehensive treatment. For poorly differentiated hypofractionated cancer or undifferentiated cancer, consolidation chemotherapy is feasible after radiotherapy.