The number of sentinel lymph nodes is not fixed, and is related to the actual situation of the patient, detection technology, etc. Generally, there are 2 to 4. Sentinel lymph nodes are the first batch of lymph nodes for primary malignant tumors and lymphatic metastasis, which can be used for judging the metastatic situation of malignant tumors, and play a suggestive role in the therapeutic plan. The number of sentinel lymph nodes is not fixed, and the number of sentinel lymph nodes in different parts of the body varies. Sentinel lymph nodes are cleared and sent for examination intraoperatively, if the pathological results are negative, there is no need to clear other lymph nodes, if there is metastasis of sentinel lymph nodes, it is necessary to continue to clear other lymph nodes, in order to achieve the clinical purpose of radical treatment. Sentinel lymph nodes have important clinical significance for the metastasis of malignant tumors, patients need to actively cooperate with the doctor to improve the relevant examination, according to the results of the examination to choose the most appropriate treatment plan for standardized treatment.