Soft Tissue Sarcoma

The term sarcoma refers to a malignant tumor that starts in one of the supporting structures of the body. A soft tissue sarcoma is a malignant tumor that grows in the soft tissues of the body. Soft tissues are the supporting structures of the body. These tissues include muscles, tendons, fat blood vessels, nerves and synovial tissues.

These malignant tumors may occur in both adults and children, however, these tumors are rare in infants and young children. Soft tissue sarcomas account for approximately three percent of the childhood cancers diagnosed yearly.

Types of Soft Tissue Sarcomas

The different types of soft tissue sarcomas are named according to the location of the first tumor. The following list describes the most common types of soft tissue sarcomas seen in children:

  • Rhabdomyosarcoma: This is the most common type of soft tissue sarcoma which is seen in children between 2 to 6 years of age or during the teenage years. This tumor usually develops in muscle tissue. These muscles are usually located around the bones.
  • Fibrosarcoma: This type of cancer is found in the fibrous tissue in the legs and arms. Sometimes this tumor arises in an area that has previously received radiation for another type of cancer. These tumors are more common in males than in females.
  • Neurofibrosarcoma (malignant schwannoma): This type of cancer is found in the nerves near the surface of the legs, arms and trunk. These tumors are uncommon in children. They are sometimes associated with a condition known as Neurofibromatosis (von Recklinghausen's disease) which causes tumors on the peripheral nerves.
  • Leiomyosarcoma: This tumor is usually found in the muscle of internal organs. The most common areas are the gastrointestinal tract; genitourinary tract and the respiratory tract. When this type of cancer spreads, it will usually go to the liver, lymph nodes, lungs, the lining of the abdominal cavity and the pancreas.
  • Synovial Cell Sarcoma (synovioma): This is an unusual tumor that occurs in the soft tissue, but the exact tissue is not known. These tumors are usually found in the feet, knees, thighs and hands. When this type of cancer spreads, it will usually go to the lungs, bones and lymph nodes. These tumors are more common in males than in females.
  • Hemangiopericytoma: These tumors are found in the vascular tissues which are the blood vessels. The primary tumor sites are usually blood vessels of the trunk and the extremities. When this cancer spreads it will usually go to the lungs, brain, bones and liver.
  • Alveolar Soft Part Sarcoma: This is a rare tumor found in muscle tissue. This is a slow-growing tumor that is usually found in the thigh or abdominal wall. When this cancer spreads it usually will occur in the lungs, bones and brain. This type of tumor is more common in females than in males.
  • Liposarcoma: This tumor is found in the adipose (fat) tissue of the arms and legs. This is usually a rapid-growing tumor with symptoms such as fever. There is a higher number of this type of tumor in the first two years of life; males get them more than females.
  • Malignant Fibrous Histiocytoma: This tumor is found in the fibrous tissues deep in the extremities such as the thighs.

What are metastases?

Metastases refers to the spread of cancer from its original location to other parts of the body. These types of tumors tend to metastasize to the lungs.

What is staging?

Staging is the process of determining the extent of the disease at the time of diagnosis. Staging is necessary to assist the physician in choosing the most appropriate treatment plan for the child. The staging systems may vary depending on the known patterns of metastasis of the sarcoma.


There is no known cause for these types of tumors. There is no evidence that these tumors are inherited or recent injury to the affected area is the cause of this disease. It is also known that this disease is not contagious.


The signs and symptoms of these tumors may vary depending on the location of the tumor and the specific type of tumor.

  • There may be pain and swelling around the affected tissue.
  • If the tumor is located in a muscle or synovial tissue, a child may experience limited and painful movement of an extremity or joint.
  • Sometimes the symptoms may be vague and go undetected for extended periods of time.


There are three methods of treatment used for soft tissue sarcomas. Frequently more than one treatment method is used to treat these types of malignant tumors. 

  1. Chemotherapy: the use of drugs to kill cancer cells. Chemotherapy not only destroys cancer cells but also affects the growth of normal cells and therefore has side effects which will be explained to you.
  2. Surgery: involves the complete or partial removal of the tumor. Some normal tissue may also be removed and lymph node sampling performed as part of the staging process. 
  3. Radiation therapy: the use of high-powered X-rays to kill cancer cells. The treatment is given in precisely measured amounts by doctors and technicians who are experts in this field.

Treatment may vary according to:

  • Type of sarcoma
  • Age of the child at diagnosis
  • Location of the tumor
  • Stage of the disease.

At the Aflac Cancer and Bleeding Disorders Service, parents are always included in the decision-making process when the healthcare team develops a treatment plan.