Although soft tissue sarcomas may develop in any part of the body, in both children and adults they are most commonly found in the trunk, arms, and legs. The primary symptom of a soft tissue sarcoma may appear as a solid mass or lump. If the mass interferes with a function of the body, it may cause other symptoms. Bone sarcomas usually present with symptoms of pain and swelling of a bone or a bone region.

If there are symptoms, a doctor may cut out a piece of tissue from the swollen area. This is called a biopsy. The tissue will be looked at under a microscope to see if there are any cancer cells. A patient may need to go to the hospital for this test.  Careful planning of the initial biopsy is important to avoid compromising a subsequent surgical cure. The selection of treatment is determined by the grade of the tumor, it is essential to have a careful review of the biopsy tissue by a pathologist who is experienced in diagnosing sarcomas. Complete staging and treatment planning by a multidisciplinary team of cancer specialists is required to determine the best treatment for someone with this disease.

There are many different kinds of soft tissue sarcoma and bone sarcoma, depending on the soft tissue or bone where the cancer begins.