The presence of blood flow signal inside the lymph node suggests that the lymph node may be a tumor metastasis. In general, normal lymph nodes are oval or bean-shaped, there is no blood flow signal inside the lymph nodes, and the cortical and medullary divisions of the lymph nodes are clear, and the normal lymph node gate can also be seen. If the lymph nodes are enlarged and round, and then there is blood flow signal inside the lymph nodes, the lymph node gate disappears, and the demarcation between the cortex and the medulla is not very clear, it may be caused by tumor metastasis. If necessary, the enlarged lymph nodes can be completely removed under local anesthesia and sent to pathology for examination, and based on the results of pathology examination, it can be confirmed whether the enlarged lymph nodes are caused by tumor metastasis.