Types of soft tissue sarcoma

Soft tissue sarcoma can grow into nearby tissue and destroy it. It can also spread (metastasize) to other parts of the body.

Although soft tissue sarcoma is rare, there are more than 50 different types. They are grouped by the type of soft tissue that the cancer cell is associated with. Common primary sarcoma types include:

• fat tissue sarcomas
• fibrous tissue sarcomas
• muscle tissue sarcomas
• blood and lymph vessel associated sarcomas
• nerve tissue sarcomas
• gastrointestinal (GI) tract sarcomas

A fat tissue sarcoma is called a liposarcoma. It is one of the most common types of soft tissue sarcoma in adults, especially those between 50 and 65 years old. About 20% of soft tissue sarcomas in adults are liposarcomas.

Liposarcoma is usually found in the extremities (arms or legs) or at the back of the abdomen behind the peritoneum (called the retroperitoneum). Depending on the type of liposarcoma, it can grow slowly or quickly.

There are different types of liposarcoma. They are named based on how the cells look under a microscope and where they are found. They include:

• well-differentiated liposarcoma
• atypical lipomatous tumour
• dedifferentiated liposarcoma
• myxoid liposarcoma
• pleomorphic liposarcoma
• myxoid pleomorphic liposarcoma

Myxofibrosarcoma is one of the most common types of soft tissue sarcoma. Itʼs most often found in adults around 60 years or older. It most often starts in the legs or arms. Myxofibrosarcomas tend to grow slowly. They often come back (recur) after they are removed and can become a more aggressive type that is more likely to spread to other parts of the body, such as the lungs or bone.

Fibrosarcoma (also called adult fibrosarcoma) is an uncommon type of soft tissue sarcoma. It’s most often found in adults aged 30 to 60 years. It most often starts in an arm or leg, the torso, or in the head and neck area. Fibrosarcoma is slightly more common in people who previously had radiation therapy treatment.

Dermatofibrosarcoma protuberans is a rare type of soft tissue sarcoma that is found in the thick, middle layer of the skin (dermis). It usually develops in young adults around 30 years old. Dermatofibrosarcoma protuberans tends to grow slowly and often starts in the torso, or in an arm or a leg. It tends to spread along the skin and may grow into deeper tissues, but it doesn’t usually spread to other parts of the body.

Solitary fibrous tumour is a slow-growing type of soft tissue sarcoma. Itʼs most often found in adults aged 50 to 60 years and can start anywhere in the body. Solitary fibrous tumour used to be called hemangiopericytoma.

Undifferentiated pleomorphic sarcoma (UPS) is a type of soft tissue sarcoma that is most often found in older adults aged 60 to 70 years. It can be found anywhere in the body. UPS used to be called malignant fibrous histiocytoma (MFH).

Leiomyosarcoma is one of the most common types of soft tissue sarcoma. Itʼs often found in middle-aged or older adults. Leiomyosarcoma starts in the smooth muscle, which is the type of muscle that works without you thinking about it (involuntary muscle). Leiomyosarcomas can develop almost anywhere in the body, but they most often form in parts of the gastrointestinal (GI) tract, like the stomach, or in large blood vessels. Leiomyosarcoma can also develop in the wall of the uterus (called uterine sarcoma) .

Rhabdomyosarcoma is the most common type of soft tissue sarcoma in children. It is rare in adults. Rhabdomyosarcoma starts in skeletal muscle, which is a type of muscle that you control to move your body (voluntary muscle). It most often starts in the head and neck area, arms, legs and torso. Find out more about rhabdomyosarcoma.

Angiosarcoma usually starts in the skin or other tissues close to the surface of the body. It can also develop in the liver, breast, heart and in the wall of the abdomen. Angiosarcoma is slightly more common in people who have had lymphedema after treatment for a different cancer.

Epithelioid hemangioendothelioma is a very rare tumour that starts in the epithelial cells that line the blood vessels. It’s most often found in the liver.

Kaposi sarcoma is a rare tumour that also develops in the blood and lymph vessels.

Malignant peripheral nerve sheath tumours (MPNSTs) are rare tumours that start in the cells that cover nerves. They can develop anywhere in the body but most often affect major nerves at the back of the abdomen (in the retroperitoneum) and in the legs. People with neurofibromatosis type 1 have a higher risk of developing an MPNST.

Malignant granular cell tumours are rare soft tissue sarcomas that can develop anywhere in the body but are most often found in the mouth, pancreas and bile duct.

The following are rare types of nerve tissue sarcomas:

• melanotic malignant nerve sheath tumour
• malignant perineuriomas

Extraskeletal bone sarcomas are a type of sarcoma that can start around the bone, but not in or on the bone itself.

Extraskeletal osteosarcoma is a rare type of soft tissue sarcoma. It is made up of bone tissue that has not hardened (osteoid) and cartilage. Most extraskeletal osteosarcomas develop in the arm or leg. They are also found near the breast, bladder, chest wall, back of the abdomen (retroperitoneum) or other internal organs.

Extraskeletal Ewing sarcoma is an uncommon type of soft tissue sarcoma. It can develop in the arm or leg.

A gastrointestinal stromal tumour (GIST) is a soft tissue sarcoma that starts in the walls of the gastrointestinal (GI) tract. It can develop anywhere along the GI tract. Most GISTs start in the stomach.

Find out more about gastrointestinal stromal tumours (GISTs).

Some soft tissue sarcomas do not look like any specific type of tissue in the body. Instead, they are defined by how they look under a microscope or by genetic changes in the tumour.

These tumours can start in different parts of the body and are not associated with a specific type of soft tissue.

Alveolar soft part sarcoma is a rare tumour. Itʼs usually found in young adults and is more common in women. It most often develops in the legs. It grows slowly but is known to spread to the lungs, brain or bone in the early stages.

Clear cell sarcoma grows slowly and usually develops in the tendons of young adults. It is like melanoma and the cells contain melanin, which is the substance that gives skin its colour. Clear cell sarcoma tends to spread to nearby lymph nodes.

Synovial sarcoma is a slow-growing tumour that is usually found in young adults. It most often develops around the joints of the knee or ankle. Despite its name, it does not come from synovial tissue.

The following sarcomas without a tissue type are rare:

• desmoplastic small round cell tumour
• epithelioid sarcoma
• extraskeletal myxoid chondrosarcoma
• intimal sarcoma
• NTRK-rearranged spindle cell neoplasm
• malignant ossifying fibromyxoid tumour
• malignant perivascular epithelioid tumour
• rhabdoid tumour