Lymphocytic infiltration is a relatively common phenomenon, mainly referring to chronic inflammatory cells in the body, or tumor cells appearing lymphocytic infiltration. When there are pathogenic microbial infections in the body, such as chronic inflammation, or the presence of benign tumors, malignant tumors, can cause lymphocyte infiltration. 1, chronic inflammation: chronic inflammation is usually manifested as chronic inflammatory cell infiltration, that is, the phenomenon of inflammatory cells in the local inflammatory aggregation. Chronic inflammatory cell infiltration is usually dominated by lymphocyte infiltration, and the right amount of lymphocyte infiltration can effectively remove foreign antigens such as bacteria and promote the dissipation of inflammation. If there is excessive lymphocyte infiltration in the body, the body may develop chronic inflammation, commonly seen in chronic gastritis, chronic hepatitis, etc.; 2. Benign tumors: Although benign tumors have a good prognosis, they are also a type of inflammatory lesions that may cause the body to produce an immune response and cause lymphocyte infiltration, which is seen to destroy the cells and blood vessel walls adjacent to benign tumors. Lymphocyte infiltration in benign tumors is commonly seen in uterine smooth muscle tumors, benign airway tumors, etc.; 3. Malignant tumors: When malignant tumors appear in the body, it may cause the body to produce a large number of lymphocytes, and lymphocyte infiltration may occur when lymphocytes are invaded by malignant tumors, commonly seen in lymphoma, gastric cancer, etc.