Soft tissue sarcoma

Soft tissue sarcomas develop in soft tissues such as fat, muscle, blood vessels, lymphatic vessels, nerves, tendons and cartilage. 

There are more than 50 types of soft tissue sarcoma. 

In adults, the most common types of soft tissue sarcoma are: 

• undifferentiated pleomorphic sarcoma (UPS) – an aggressive type of soft tissue sarcoma that often spreads, or comes back after treatment. It is most common in people aged 50–70 years 
• leiomyosarcoma – a tumour in the smooth muscle, often in the limbs, abdomen or uterus 
• liposarcoma – a tumour in fat cells, often in the trunk, limbs and abdomen 
• angiosarcoma – a tumour in the blood vessels or lymphatic vessels  
• malignant peripheral nerve sheath tumour – a tumour in the lining of nerves, often in the deep tissue of the arms, legs and trunk 
• fibroblastic sarcoma (fibrosarcoma) – a tumour that develops in the fibrous tissues of the body, often in the limbs, skin and trunk 
• gastrointestinal stromal tumour (GIST) – a tumour that starts in the digestive tract, often in people aged 50–80 years. This type of tumour is treated differently to other soft tissue sarcomas 
• Kaposi sarcoma – a tumour caused by a virus that can cause disease in people with a compromised immune system, such as people with AIDS. It most commonly affects the skin, mouth and internal organs 
• uterine sarcoma. 

In children, the most common types of soft tissue sarcoma are: 

• rhabdomyosarcoma – an aggressive type of sarcoma in skeletal muscles. Rhabdomyosarcomas are most common in children aged less than 10 years, although they can also develop in teenagers and adults 
• synovial sarcoma – a tumour that develops in cells around joints and tendons. It is more common in children and young adults, but can occur in older people. 

Primary bone sarcoma

Primary bone sarcoma starts in the bone. This is different from bone metastases, which have spread to the bones from cancer in another part of the body, such as the breast or lung. 

Bone sarcomas are more common in children and teenagers than in older adults. They include: 

• osteosarcoma – the most common primary bone cancer, which usually occurs at the ends of the long bones, especially around the knees 
• Ewing sarcoma – common sites are the pelvis, the chest wall and the middle of the long bones in the legs. It may also form in soft tissue.