Sarcomas are large group of malignant tumors that can be found almost anywhere in the body and can strike young and old alike. Soft tissue sarcomas can develop in every type of soft tissue in the body, including nerves, fat, muscle and blood vessels. Sarcomas can also occur in almost any organ, including the lungs, heart, gastrointestinal tract, liver, kidney and the extremities.
More than half of soft tissue sarcomas—about 60% —occur in the arms and legs. Other common sarcomasites include the trunk (20% of cases), the abdomen (15%) and the head and neck region. For more information on sarcomas that occur in cartilage and bone, view bone cancer.
Types of Sarcoma
There are more than 30 different types of malignant soft tissue sarcoma. They can be simply categorized according to the types of cells affected: fat, smooth muscle, skeletal muscle, nerve tissue, joints, blood and/or lymph vessels and fibrous tissue. There is also a category for sarcomas of undetermined or mixed type. Some of the most common types of sarcoma are listed below:
Liposarcoma appears as a malignant form of fatty tissue and is most often found in the legs (back of the knee and thigh), or the posterior abdominal area. Liposarcomas can be slow-growing or aggressive. Most patients are between the ages of 50 and 65 years.
Leiomyosarcoma appears as a malignant form of smooth muscle, which is found in the lining of the gastrointestinal tract, womb, blood vessels, skin and other organs. The abdomen, extremities and posterior abdominal area are the most common site for leiomyosarcomas, but internal organs and blood vessels may also be affected.
Pleomorphic Sarcoma and Malignant Fibrous Histiocytoma (MFH) occurs in fibrous tissue in the arms and legs. It is a common form of malignant sarcoma in older adults, and has a tendency to spread to distant areas of the body, particularly the lungs.
Rhabdomyosarcoma has the appearance of rhabdomyoblasts, immature cells that form the body’s skeletal muscles. It occurs in two age groups: children under five years of age, and adolescents and older individuals.
The incidence in Spain is similar to other developed countries. Rhabdomyosarcoma represents 8% of all child tumours.
Since rhabdomyosarcoma can be a very fast-growing tumor, immediate treatment is crucial.
Fibrosarcoma originates in the fibrous tissue found at the end of long bones in the arms and legs, and in the trunk. Fibrosarcomas generally occur in adults under 60, but infants and the elderly can also be affected.
Synovial sarcomas are composed of cells that are similar to cells that line joints, although it's not believed to arise from the synovium, which produces fluid to lubricate the joints. These tumors are usually found in the knees, ankles, hips and shoulders. Adolescents and young adults are most likely to have synovial sarcomas, although they can occur later in life.
Gastrointestinal stromal tumors (GIST) occur in the interstitial cells of Cajal (ICC), which are special cells that line the walls of the gastrointestinal tract. These cells signal muscles to contract to move food and liquid along the digestive tract. More than half of GIST tumors are found in the stomach, but can also occur in the small intestine, esophagus, colon and rectum. Most GIST patients are 50 to 70 years of age.
Sarcomas close to the surface of the skin may be easily detected, but those deeper in the body may not become apparent until they get large. Only about half of sarcomas are detected in the early stages before they spread. Sarcoma Symptoms may include:
- A new lump
- A lump that appears to be growing in size
- Abdominal pain (when the tumor becomes large enough to affect nearby organs)
- Blood in the feces or vomit
- Unexplained anemia
- A new pain
- After some type of injury
Having one or more of the symptoms listed above does not necessarily mean you have a soft tissue sarcoma. However, it is important to discuss any symptoms with your doctor, since they may indicate other health problems.