|
|
Liposarcoma is a malignant soft tissue tumor (cancer that originates in soft connective tissues of the body) that develops in fat tissue. It is most often found in the abdominal cavity or extremities, usually the thigh or upper arm, but they can be found anywhere in the body.
|
|
|
|
|
|
The exact cause of soft tissue sarcomas is not entirely understood, however, studies have indicated that genetic alterations may play a role. Researchers have studied a small number of families that contain several members of one generation who have developed soft tissue sarcomas. In addition, limited studies have shown a possible link between soft tissue sarcomas and the development of other types of cancer.
Certain inherited diseases are also associated with an increased risk of developing soft tissue sarcomas. These include people with Li-Fraumeni syndrome (which involves alterations in the p53 gene) or neurofibromatosis (which involves alterations in the NF1 gene). For some soft tissue tumors, there seems to be an association with an Epstein-Barr virus infection. Liposarcoma rarely arises from lipoma, a benign tumor of fatty tissue.
|
|
|
|
|
Because liposarcoma affects tissue that is elastic and easily moved, a tumor may exist for a long time before being discovered, growing large and pushing aside surrounding tissue. The following are the most common symptoms of soft tissue sarcomas. However, each child may experience symptoms differently:
- A painless swelling or lump
- Pain or soreness caused by compressed nerves or muscles
- Limping or other difficulty using the legs and feet
- Diminished range of motion in the affected area
The symptoms of liposarcoma may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.
|
|
|
|
|
|
In addition to a complete medical history and physical examination, the most conclusive diagnostic procedure for liposarcoma is a biopsy, a single tissue sample taken from the tumor through a simple surgical procedure. The tumor's cellular appearance under a microscope enables doctors to distinguish it from other types of cancer and helps doctors determine how aggressive the tumor is.
Your child will likely undergo various imaging studies that will include one or more of the following:
- x-rays - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. X-rays are very useful in the diagnosis of soft tissue tumors and frequently they allow physicians to distinguish benign from malignant tumors. An x-ray is the first diagnostic study, and often it gives the doctor information regarding the need for further testing.
- Magnetic Resonance Imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body. This test is used to assess the size and extent of the mass and its relationship to surrounding muscle, bone, nerves and blood vessels.
- Computerized Tomography scan (also called CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices)both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat and organs. CT scans are more detailed that general x-rays. They are used primarily to assess the chest and lung for metastatic tumors.
Other tests include:
- Complete blood count (CBC) - a measurement of size, number and maturity of different blood cells in a specific volume of blood
- Blood tests - (including blood chemistries)
|
|
|
|
|
|
Once liposarcoma has been diagnosed, the tumor is staged. This process indicates whether or not the tumor has spread from its original location, and, if so, how far it has spread. The stage of a tumor and how aggressive the tumor is suggests which form of treatment is most appropriate, and gives some indication of the prognosis for the condition. In most cases, liposarcoma does not spread beyond its local location.
|
|
|
|
|
Specific treatment for liposarcoma will be determined by your child's physician based on:
- Your child's age, overall health, and medical history
- Extent and location of the disease
- The presence or absence of metastasis
- Your child's tolerance for specific medications, procedures or therapies
- How your child's doctor expects the disease may progress
- Your opinion and preference
Treatment for liposarcoma will involve a multidisciplinary team of health professionals that will include pediatric oncologists, surgeons, orthopaedic surgeons, and radiotherapists. Treatment options will vary greatly, depending on your child's individual situation. Your child's physician and other members of your care team will discuss these with you in-depth.
Surgery is the mainstay of treatment for most soft tissue sarcomas, particularly for liposarcoma in children, which tends to be locally aggressive. Surgery includes biopsy of surgical removal of the entire tumor. It is especially important for surgeons to remove wide margins of surrounding healthy tissue, to ensure there are no remaining cancer cells.
In cases where the tumor is found in the extremities, it may be necessary to remove all or part of the limb. In most cases limb-sparing surgery is used to avoid amputation. The following is a summary of these procedures:
- Limb-salvage surgery: Limb-salvage surgery is indicated only if your child's orthopedic surgeon determines that it is possible that the tumor, and wide margins of healthy tissue surrounding the tumor, can be removed.
Through limb-salvage surgery, all of the tissue involved with the tumor, including some degree of muscle surrounding it and nearby lymph nodes, are removed, unaffected tendons, nerves and vessels are saved. If bone is also removed, it is usually replaced with a bone graft or with a metal rod. Subsequent surgery may be needed to repair or replace rods, which can become loose or break. Patients who have undergone limb-salvage surgery need intensive rehabilitation. It may take as long as a year for a patient to regain full use of a leg following limb-salvage surgery. Some patients who undergo limb-salvage procedures may eventually have to undergo amputation.
- Amputation: If the tumor is located in a limb and your child's orthopedic surgeon determines that the tumor cannot be removed because, for example, it involves the nerves and blood vessels, amputation may be the only option.
During the operation, doctors ensure that muscles and skin form a cuff around the amputated bone. A cast is applied in the operating room which permits a temporary artificial leg (prosthesis) to be applied during the first few post-operative days for walking. Crutches are used for several weeks. As the swelling decreases (10 to 14 days) the patient is fitted for a plastic, temporary socket and prosthesis, which is used for 3 to 4 months until the stump is healed sufficiently to accept a permanent artificial leg. The advantages of an amputation are that it is a simple operation with minimal chances of surgical complication and it definitively removes the local tumor. The functional outcome is good with the modern prostheses available today and with "immediate-fit" prostheses applied in the operating room. Although the patient will probably have a limp with above-the-knee amputations, the procedure is functional and stable. He/she will be able to walk, climb stairs, swim (with the prosthesis on or off) and participate in many sports such as skiing, basketball, baseball, and tennis although running will be limited. The functional limitations are left to the imagination and determination of the patient.
|
|
|
|
If surgery to remove the entire tumor isn't possible or the tumor has metastasized, surgery may be combined with radiation therapy, which uses high energy rays (radiation) from a specialized machine to damage or kill cancer cells and shrink tumors. Because of risks associated with high doses of radiation in young children, radiation is used only if surgery alone is ineffective.
No evidence exists that chemotherapy is an effective contributing treatment against liposarcoma. However, numerous studies are being performed to investigate its use.
The following are vital to successful treatment of liposarcoma:
- Supportive care - any type of treatment to prevent and treat infections, side effects of treatments and complications and to keep your child comfortable during treatment.
- Continuous follow-up care - a schedule of follow-up care determined by your child's physician and other members of you care team to monitor ongoing response to treatment and possible late effects of treatment.
|
|
|
|
|
Prognosis greatly depends on:
- The extent of the disease
- The size and location of the tumor
- A presence or absence of metastasis
- The tumor's response to therapy
- The age and overall health of your child
- Your child's tolerance of specific medications, procedures, or therapies
- New developments in treatment
As with any cancer, prognosis and long-term survival can vary greatly from individual to individual. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a child diagnosed with liposarcoma. Side effects of radiation as well as recurrence of the disease, can occur in survivors of this condition.
|
|
|
|
|
|
Children's Hospital and Dana-Farber Cancer Institute are conducting numerous research studies that will help clinicians better understand and treat soft tissue sarcomas.
Other types of treatment currently being studied include:
- Angiogenesis inhibitors - substances that may be able to prevent the growth of tumors by blocking the formation of new blood vessels that feed the tumors.
- Biological therapies - a wide range of substances that may be able to involve the body's own immune system to fight cancer or lessen harmful side effects of some treatments.
- Chemotherapy - researchers are looking into different chemotherapy drugs that may prove affective on children with liposarcoma.
|
|
|
|
|
|
|
Liposarcoma
