Learn about soft tissue sarcoma

Sarcomas are tumors that begin in the connective tissues of the body. Connective tissues include the bones, cartilage, fat, muscles, nerves, deep skin and blood vessels. Sarcomas are rare; it is estimated that nearly 12,000 new cases of soft tissue sarcoma are diagnosed each year in the United States. These tumors occur more often in children than adults, accounting for about 15 percent of all pediatric cancers and about one percent of adult cancers.

Sarcoma is subdivided into two main types: bone sarcomas and soft tissue sarcomas.

Bone sarcoma

Bone sarcoma is a tumor that starts in a bone. It is different from cancer that spreads to bone from another site, such as the breast or lung, which is called metastatic cancer. There are three types of primary bone sarcoma (see Figure 2 and Table 2).

  • Osteosarcoma – the most common type of bone cancer, is also called osteogenic sarcoma. These sarcomas occur most often in people 10-30 years old and develop primarily in the legs (around the knee) and in the upper arm.
  • Chondrosarcoma – the second most common primary bone cancer, which develops in cartilage. Cartilage is fibrous tissue mixed with a gel-like substance, making it softer than bone but harder than most tissues in the body. Chondrosarcoma can occur anywhere in the body where cartilage is present, but most frequently develops in the pelvis, legs or arms.
  • Ewing sarcoma – a rare bone sarcoma, occurs more frequently in children and young adults. It usually develops in the pelvis and legs.

Table 2. Types of bone sarcoma

Type of bone sarcoma Tissue of origin Typical age (years) Most common sites
Most common types
Osteosarcoma Bone 10-30 Leg (near the knee), upper arm (near the shoulder)
Chondrosarcoma Cartilage 40 and older Pelvis, leg, arm
Ewing sarcoma Bone 10-20 Pelvis, leg
Other types
Chordoma Bone 40-70 Skull base, spine, tailbone
Adamantinoma Bone 20-50 Lower leg
Malignant giant cell tumor of bone Bone 20-60 Knee

Soft tissue sarcoma

Soft tissue sarcomas are more common than bone sarcomas and can develop in any of the soft tissues anywhere in the body (see Figure 1). Soft tissue sarcomas are named according to the type of tissue in which they develop. For example, sarcoma that develops in fat tissue is called liposarcoma and sarcoma that develops in blood vessels is called angiosarcoma.

Soft tissue sarcoma occurs most frequently in the arms or legs but is also found in the head and neck, internal organs (especially the stomach), trunk and the back of the abdominal cavity (the retroperitoneum). There are approximately 50 different types of soft tissue sarcoma (see Table 1). Rhabdomyosarcoma is the most common soft tissue sarcoma in children but is rare in adults.

Table 1. Types of soft tissue sarcoma

Type of soft tissue sarcoma Tissue of origin Typical age (years) Most common sites
Most common types
Undifferentiated pleomorphic sarcoma (previously called
malignant fibrous histiocytoma)
Uncertain 50-70
Leg; may also develop in the retroperitoneum (behind the abdomen) and head and neck
Gastrointestinal stromal tumors
Stroma (supportive connective tissue) of the stomach and intestines
50 and older Wall of the stomach and the small intestine
Leiomyosarcoma Smooth muscle tissue Average: 60 Uterus, small intestine or stomach
Liposarcoma Fat tissue 30-60 Thigh, behind the knee, retroperitoneum
Synovial sarcoma Tissue around joints 15-35 Near the foot, ankle and hand
Other types
Alveolar rhabdomyosarcoma Skeletal muscle Adolescents and young adults Large muscles of the trunk, arm, leg
rhabdomyosarcoma (previously called pleomorphic
Skeletal muscle Over the age of 30 Large muscles of the trunk, arm, leg
Botryoid rhabdomyosarcoma Skeletal muscle Average age: 7 Genital region and urinary tract
Skeletal muscle Under age 10
Anywhere, but often in head and neck, and around the eye
Alveolar soft-part sarcoma Connective tissue Young adults Legs or extremities
Angiosarcoma Inner lining of blood vessels 60-70 Skin, breast, liver, spleen, head and neck
Desmoid tumors
(aggressive fibromatoses)
Connective tissue that forms tendons and ligaments 10-40
Intra-abdominal mesentery (tissue that attaches organs to the wall of the abdomen), arm, leg
Desmoplastic small round cell tumor
Connective tissue that forms tendons and ligaments Adolescents and young adults Abdomen
Epithelioid sarcoma Skin 20-39 Arm, hand, feet
Fibrosarcoma Fibrous tissue 35-55 Thigh, knee, arm and trunk
Hemangiodendothelioma Inner lining of blood vessels 20-40 Soft tissues or internal organs such as liver or lung
Malignant peripheral nerve sheath tumors
Cells that surround a peripheral nerve (nerves that connect the central nervous system — spinal cord and brain) with other parts of the body
20-50 Upper part of the arm and leg, trunk


Symptoms associated with soft tissue sarcoma depend on its location. The first sign of a soft tissue sarcoma that develops in an arm, a leg or the trunk is typically a painless lump. Sometimes, though, pain is a symptom, as with synovial sarcoma. An abdominal mass is often found with a soft tissue sarcoma in the retroperitoneal area, and pain occurs in about half of people with a soft tissue sarcoma in this site. People with gastrointestinal stromal tumors (GISTs) may have digestive symptoms, such as nausea, vomiting, a feeling of being full after eating a small amount of food or loss of appetite.

Risk factors

Although there is no known cause of sarcomas, certain factors can increase an individual’s risk of developing a soft tissue sarcoma. For example, people with a family cancer syndrome may be at an increased risk for the development of sarcoma. These diseases include Li-Fraumeni syndrome, Gardner syndrome, Gorlin syndrome, tuberous sclerosis, neurofibromatosis type I (also known as von Recklinghausen disease), Werner syndrome and retinoblastoma.

Additional risk factors include exposure to radiation therapy as treatment for another type of cancer, damage to the lymph system (possibly from cancer surgery or radiation) and exposure to certain workplace chemicals, including vinyl chloride monomer or dioxin. It is important to remember that most individuals with sarcoma do not have any risk factors and that sarcoma never develops in some people who do have a risk factor.

This section

This section focuses on soft tissue sarcoma in adults. For additional information on sarcoma, either in general or about specific types of sarcoma, please see additional resources listed below.

Although a sarcoma diagnosis can be overwhelming, empower yourself by learning about your specific tumor and your treatment options so you can make informed decisions through the course of your journey. By becoming an active partner, you make your health care team immeasurably stronger and more effective. Knowledge leads to sound choices, which bring comfort and hope.


Questions to ask your medical team

  • What kind of sarcoma do I have?
  • Should I look into a clinical trial?
  • What resources are available to me?
  • Do you recommend a second opinion from a pathologist too?

Additional Resources




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