What Is Sarcoma?

Sarcoma is cancer that starts in the structural tissues that hold your body together, like the bones or soft tissues. Examples of soft tissues include:

  • Muscles
  • Blood vessels
  • Fibrous tissue
  • Fat
  • Nerves

Sarcoma is rare. There are more than 50 types of sarcomas, but they only make up about 1 in 100 cancers.

Sarcomas are grouped into two categories based on where they start:

  • Bones
  • Soft tissue

Sarcomas can occur anywhere in the body. Most are found in the arms, legs, chest and abdomen (belly).

Bone Sarcoma

Bone sarcoma is a tumor that starts in a bone. The most common ones are:

  • Osteosarcoma – The most common bone cancer in adults and children
  • Chondrosarcoma – The second-most common bone cancer in adults
  • Ewing sarcoma – The second-most common bone cancer in children

Soft Tissue Sarcoma

Soft tissue sarcoma is a type of cancer that starts in supportive tissue that holds your body together, known as the soft tissues. Examples include your muscles, fat, fibrous tissue, nerves and blood vessels.

Soft tissue sarcomas can start in soft tissue anywhere in your body. There are more than 50 types of soft tissue sarcomas.

The most common ones in adults are:

  • Undifferentiated pleomorphic sarcoma (sometimes called malignant fibrous histiocytoma) – Most common in legs and arms
  • Liposarcoma – Starts in your fat cells, and most common in legs, arms and abdomen
  • Leiomyosarcoma – Starts in the involuntary muscles (smooth muscle), such as in the urinary system, digestive system, uterus and blood vessels
  • Gastrointestinal stromal tumor (GIST) – Starts in the digestive system

There are many types of lumps in the soft tissues of your body. Most are not cancer. Some of these include:

  • Fatty tumors called lipomas
  • Fluid-filled cysts
  • Collections of abnormal blood vessels, called hemangiomas