Local soft tissue infiltration is the slow infiltration of fluid into soft tissues, the infiltration of abnormal cells into human tissues or the appearance of body cells that should not be present under normal circumstances, and the expansion of certain diseased tissues into the surrounding area. So, how should the differential diagnosis of local soft tissue infiltration symptoms be made? The following is a brief description of the phenomenon: the invasion of abnormal cells or the appearance of organism cells that should not be present under normal circumstances in human tissues, as well as the peripheral expansion of certain diseased tissues. The appearance of abnormal substances or excessive accumulation of certain pre-existing substances within the cells or in the interstitium is also called infiltration. Infiltration is also seen in treatment, except for infiltration with drugs for therapeutic purposes and infiltration of various inflammatory cells in inflammatory foci, any other infiltration is harmful to the organism, and the size of the damage depends on the nature and amount of the infiltrated material and the impact on the function of the involved organs. The phenomenon that malignant tumor cells can infiltrate the surrounding normal tissues and distribute abnormally in the tissue interstices in terms of quality and quantity is called tumor cell infiltration, which is the manifestation of a series of processes such as tumor cell adhesion, enzymatic degradation, movement, and proliferation within the stroma, and is often characteristic of malignant tumors. Cellular carcinogenesis from the cellular level cancer occurs as an extremely fortuitous event, and genetically cancer all develops from a single cell, from a cell that has lost control of its proliferation. In addition to uncontrolled growth, cancer cells can also locally invade the surrounding normal tissues or even metastasize to other parts of the body through the body’s circulatory system or lymphatic system, without restriction, and can proliferate for a long time.