Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Adult Soft Tissue Sarcoma ?
    ### Response:
    A sign of adult soft tissue sarcoma is a lump or swelling in soft tissue of the body. A sarcoma may appear as a painless lump under the skin, often on an arm or a leg. Sarcomas that begin in the abdomen may not cause signs or symptoms until they get very big.
    