Lymph node biopsy is a minor surgery and is performed clinically using local infiltration anesthesia, that is, local infiltration after doubling the dilution of 2% lidocaine, and complete removal or partial removal of the lymph nodes for pathological examination. Lymph node biopsy is mainly used for two major types of diseases: 1. Most commonly, when there are primary malignant tumors, such as gastric, intestinal or esophageal cancer, enlarged lymph nodes in the neck and inguinal region and metastasis is highly suspected, the chance of surgical radical resection is lost when distant metastasis occurs, or it is difficult to take local material to confirm gastric, intestinal or esophageal cancer, lymph node biopsy can be used to clarify whether cancer cells can be found. If cancer cells can be found, it means that distant metastasis has occurred and only palliative treatment such as chemotherapy can be used; 2. When fever of unknown origin is suspected, lymph node biopsy may be needed for hematological diseases such as lymphoma.