Sarcomas are divided into two main types:
- Soft tissue sarcomas. These develop from soft tissues, such as muscles, fat, nerves, blood vessels, fibrous tissues, or deep skin tissues. About 80 percent of sarcomas begin in soft tissues.
- Bone cancers. Bone cancers, also called osseous sarcomas, start in the bone. Bone cancers are much less common than benign (noncancerous) bone tumors or secondary cancers that spread to the bone from other locations (such as the lung or breast).
Sarcomas are further classified based on the specific type of cell that makes up the cancer. This is known as the sarcoma, or histologic (tissue-structure), subtype. There are more than 70 sarcoma subtypes. The progression of and prognosis for any particular sarcoma depends on the subtype as well as the grade (how abnormal the cancer cells appear under a microscope) and the tumor size.
Subtypes of Sarcomas
Sarcoma subtypes are named based on the surrounding tissue, the affected area of the bone, or the type of cells creating the tumor. Here are the most common subtypes of sarcoma.
- Angiosarcoma. These tumors resemble blood or lymphatic vessels.
- Chondrosarcoma. These tumors develop from cartilage cells.
- Ewing’s sarcoma. This subtype arises from very primitive cells in the body. It can start in either soft tissue or bone.
- Fibrosarcoma. This is cancer of fibrous tissue.
- Gastrointestinal stromal tumor. This is the most common sarcoma of the gastrointestinal tract.
- Leiomyosarcoma. These tumors develop from smooth muscle in abdominal and pelvic organs and blood vessels. (Unlike skeletal muscle, which you can control voluntarily, smooth muscle isn’t controlled consciously.)
- Liposarcoma. This subtype develops from fat tissue, most often in the back of the abdominal cavity (retroperitoneum) but also in the soft tissues of the limbs.
- Malignant peripheral nerve sheath tumor. These tumors arise out of nerves or related tissue outside of the brain and spinal cord.
- Osteosarcoma. This subtype develops from cells that form bone.
- Pleomorphic sarcoma. This soft tissue sarcoma usually occurs in the limbs (often the legs) and may also occur in the abdomen.
- Rhabdomyosarcoma. These tumors resemble developing skeletal muscle. They most commonly grow in the arms or legs but can also develop in the head or neck or in the urinary or reproductive organs.
- Synovial sarcoma. Synovial sarcoma can arise in any location in the body and often appears in young adults.
The most common soft tissue sarcomas in adults are gastrointestinal stromal tumor, leiomyosarcoma, liposarcoma, and pleomorphic sarcoma. The most common bone cancer is osteosarcoma.