There are many types of soft tissue sarcoma, and they tend to grow and develop differently. The most common types are described below. Your doctor will be able to give you more details about which type of sarcoma you have. Each type of sarcoma is named after the type of cell from which it has grown, rather than the part of the body in which it started.

These sarcomas start in cells called fibrocytes, which make up the fibrous tissues that join together the inner structures of the body: for example, muscles to bones. They are most commonly found on the arms, legs or trunk, but can occur deeper in the body. Most people first notice them as a painless, firm lump.

This is a type of fibrous sarcoma and the most common type of sarcoma in older people. They were previously called malignant fibrous histiocytomas (MFH). It is not clear which type of cell they start from. Myxofibrosarcomas can affect any part of the body, but most commonly occur in the arms or legs.

These tumours are another type of fibrous sarcoma. They are slow-growing and are sometimes said to be halfway between a fibrosarcoma and a benign fibroma (a non-cancerous tumour of fibrous tissue). Desmoid tumours do not tend to spread to other parts of the body, but can spread into nearby tissues and so are usually treated in a similar way to sarcomas.

These sarcomas start in the body’s fat cells. They can grow anywhere in the body and most commonly affect middle-aged people. Some grow very slowly (taking many years to develop) and others more quickly.

Synovial sarcomas usually start near to joints, such as the knee or elbow, but can occur in any part of the body. They usually appear as hard lumps and are more common in younger adults.

Rhabdomyosarcomas grow in the active muscles of the body that we can control. These muscles are known as skeletal muscle or striated muscle. Rhabdomyosarcomas occur mostly in the head, neck and pelvis, but can occur in the arms or legs. There are three sub-types of rhabdomyosarcoma: embryonal, alveolar and pleomorphic.

Embryonal rhabdomyosarcomas tend to occur more commonly in children, while alveolar rhabdomyosarcomas occur more in the limbs of teenagers and young adults. Pleomorphic rhabdomyosarcoma tends to occur in middle-aged people.

Leiomyosarcomas start from smooth muscle that is not under our conscious control. Smooth muscle is also called involuntary muscle and forms the walls of the womb, stomach, intestine and the blood vessels. Leiomyosarcoma is one of the more common types of sarcoma and can occur anywhere in the body.

These sarcomas arise in the cells that cover nerve cells and can occur anywhere in the body. The cells around the nerve cells are called schwann cells. MPNST can also be called malignant schwannomas or neurofibrosarcomas. They most commonly occur in people who have a rare genetic disorder called neurofibromatosis (von Recklinghausen’s disease).

Angiosarcomas start from the cells that make up the walls of blood or lymph vessels. If they develop from blood vessels they are called haemangiosarcomas. If they start from the lymph vessels they are called lymphangiosarcomas. Angiosarcomas sometimes arise in a part of the body that has been treated with radiotherapy many years before.

GISTs are sarcomas that develop from the connective tissues in the walls of the digestive system. The digestive system is often called the gastrointestinal (GI) tract. This type of tumour may also be called GI stromal sarcoma. They behave differently from other types of sarcoma and are treated very differently.

Although Kaposi’s sarcoma is a type of sarcoma, it differs from other sarcomas in the way it develops. It starts from cells in the skin. Coloured patches or lumps can develop in the skin, in the mouth, and in the lymph nodes or internal organs such as the lung, liver or spleen.

Kaposi’s sarcoma can affect people with a weakened immune system, including people with HIV and Aids. Other types can affect people of Jewish, Italian and West African origin. Kaposi’s sarcoma is treated differently to other types of soft tissue sarcoma.

There are other, much rarer, types of sarcoma. These include:

• alveolar soft part sarcoma
• dermatofibrosarcoma protuberans (DFSP)
• desmoplastic small round cell tumours
• epithelioid sarcomas
• extraskeletal myxoid chondrosarcomas
• giant cell fibroblastoma (GCF).

Cancerbackup nurses can give you information about these rarer types of sarcoma.

Ewing’s tumours are a type of bone sarcoma, but about a third of all Ewing’s tumours develop in the soft tissue and are known as extra-osseous Ewing’s tumours. Soft tissue Ewing’s sarcomas tend to behave differently to other soft tissue sarcomas and are usually treated in a similar way to bone sarcomas.

Soft tissue sarcomas also occur in children, particularly some types of rhabdomyosarcoma. Their symptoms and treatment may differ from those in an adult with the same sarcoma.

Our section on children's cancer discusses the treatment of children's cancers and includes information about some types of sarcoma that occur in children.