Does sarcoma usually cause many symptoms?

Depends: It depends on the type of sarcoma, location of the lesion and stage of lesion. Sarcomas are cancers of the connective tissue, muscle and bone.

Varies: Sarcomas can arise in bones and soft tissues. In bones they usually cause pain and a mass (swelling). In soft tissues they present with a mass, but are rarely painful. Any soft tissue mass need to be evaluated by a doctor, even if not painful. While sarcomas are very rare, it's not safe to assume that a mass is benign just because it's painless. Rarely sarcomas of bone cause the bone to break.