The soft tissue sarcomas are a group of cancers which develop from a number of different supportive tissues in the body including fibrous tissue, muscle, ligaments, tendons and fat.

Soft tissue sarcomas are rare. They make up less than 1% of all cancers, with only about 1200 new cases being diagnosed each year in the United Kingdom. Relatively speaking, they are actually more common in children than adults, making up about 8% of all cancers in those under the age of 15.

Over the years more than 60 different types, or subtypes, of soft tissue sarcoma have been identified. As the group of tumours as a whole are quite rare this means that some forms of the condition are very rare indeed. The large number of different types has also lead to problems in classifying the soft tissue sarcomas. Most have names based on the type of normal cell from which the cancer might have started but for some soft tissue sarcomas there does not seem to be any equivalent normal cell and so special names have been given to these tumours. Liposarcomas get their name because they appear to develop from fat cells in the soft tissues of the body.

Various types of liposarcoma include:

• atypical lipomatous tumour or grade 1 or well-differentiated liposarcoma, which is seen most often in the abdomen and can grow to a large size without very little likelihood of any spread elsewhere.
• pleomorphic liposarcoma or dedifferentiated or high-grade liposarcoma, which can occur in the abdomen or the limbs and grows more rapidly and behaves more aggressively with quite a high chance of spread to the lungs.
• myxoid liposarcoma, which is commonest in the abdomen and is intermediate between the other two types in terms of its behaviour with a tendency to spread to other fatty tissue sites in the abdomen and around the spine rather than the lungs

Liposarcomas usually starts as a painless, swelling in the soft, non-bony, tissues. They vary from slow growing to quite rapidly growing. Generally the tumours cause few other symptoms.

Like most other soft tissue sarcomas the treatment for liposarcomas is surgery, wherever possible, to remove the growth. If the tumour is of low grade appearance under the microscope then this may be all the treatment that is required. If the tumour is of a higher grade then surgery is usually followed by a course of radiotherapy to reduce any chance of the cancer coming back. Occasionally a liposarcoma is too large or stuck down to make an operation possible, but the surgeon feels that it might become operable if it could reduced in size. In this situation the doctors may recommend a course of radiotherapy or chemotherapy before the operation in the hope that it may shrink the sarcoma and make it more operable. If, as often happens, the liposarcoma is in a part of the body where surgery is impossible or dangerous then radiotherapy is used and often combined with chemotherapy.