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 sarcoma types 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. Although it is the most common soft tissue cancer in children, only about 350 cases are diagnosed each year in the United States. 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.