Malignant soft tissue tumors have the following characteristics: 1. Rapid growth rate. Often, the volume can be doubled to several times in a few months; 2. No obvious pain. Most of the malignant tumors are not accompanied by obvious pain during the growth process, unless the tumor compresses the nerve; 3. Inflammatory masses are often accompanied by obvious skin redness, swelling and pain; 4.Recurrence soon after resection. If the mass in your body recurs again or repeatedly after excision, you should definitely pay enough attention to it, because the possibility of malignancy is very high in this way; 5. The boundary of the mass is not smooth. Most malignant soft tissue tumors become bumpy when touched, but there are also very smooth ones, such as liposarcoma; 6. Prolonged skin ulceration. If the wound does not heal with change of medication and accompanied by foul odor, the possibility of skin malignant tumor should be considered; 7. Single or multiple lymph nodes with diameter more than 1cm in the armpit, groin and other parts. It is very likely to be a manifestation of lymphoma. If your body grows lumps or ulcers with the above characteristics, please go to a specialist hospital promptly.