Local soft tissue infiltration is the slow infiltration of fluid into soft tissue, the infiltration of abnormal cells into human tissue or the appearance of body cells that should not be present under normal circumstances, and the expansion of certain diseased tissue into the surrounding area. The appearance of abnormal substances or excessive accumulation of certain pre-existing substances within the cells or in the interstitium is also called infiltration. Some degeneration or deposition is also called infiltration. So, what are the causative factors of local soft tissue infiltration in patients? Here is a brief introduction: Tumor cells can infiltrate the surrounding normal tissues, which is called tumor cell infiltration and is often a characteristic of malignant tumors. Due to the rapid growth of tumor, it invades into the surrounding tissue interstices, lymphatic vessels and blood vessels, just like the roots of trees growing into the soil, infiltrates and destroys the surrounding tissues, the tumor often has no envelope or incomplete envelope, and is not clearly demarcated from the surrounding tissues. When palpated clinically, the tumor is fixed and immobile. Infiltration is also seen in treatment. Except for the use of drug infiltration for therapeutic purposes and the infiltration of various inflammatory cells in inflammatory foci, any other infiltration is harmful to the organism, and the size of its damage depends on the nature and amount of the infiltrated material and the effect of the function of the involved organs.