Cancer starts when cells start to grow out of control. Cells in nearly any part of the body can become cancer and can spread to other areas.
There are many types of soft tissue tumors, and not all of them are cancerous. Many benign tumors are found in soft tissues. The word benign means they're not cancer. These tumors can't spread to other parts of the body. Some soft tissue tumors behave in ways between a cancer and a non-cancer. These are called intermediate soft tissue tumors.