What is rhabdomyosarcoma?
Rhabdomyosarcoma is a type of soft tissue tumor, or sarcoma, arising from muscle cells. Although it can occur in any muscle tissue, it is generally around the head and neck area, the pelvis, or in the arms and legs. Rhabdomyosarcoma occurs slightly more frequently in males and usually affects children between the ages of two and six. It is not known what causes the tumor. It is not contagious, and nothing you have done or not done is responsible for your child's tumor.
What are the symptoms of rhabdomyosarcoma?
A noticeable lump or swelling is present in almost all cases. Other symptoms depend on the location. If the growth is near the eyes, a vision problem and outward swelling of the eye may develop. If the neck is involved, there may be hoarseness or difficulty swallowing. Sometimes the mass may press on nearby structures and cause problems. For example, a mass near the bladder or rectum may cause difficulties with urination or bowel function. Pain, weakness, or unusual sensations may be present in the area where the tumor started or areas where it has spread.
How is rhabdomyosarcoma diagnosed?
Rhabdomyosarcoma may spread (metastasize) to other parts of the body. These areas can include the lungs, liver, brain, bones, or bone marrow. Your child will need to undergo various diagnostic tests in order to determine the location of the tumor and if it has spread.
The tests may include any or all of the following:
- X-rays. X-rays of the tumor site and surrounding area look at size and extent of the tumor. X-rays of the chest look for spread of the tumor.
- Bone scan. A dye injection x-ray test helps detect tumor spread in bones.
- Bone marrow aspirate & biopsy. This test looks for tumor spread in the bone marrow.
- Computed tomography (CT scan). This test can more accurately determine the tumor site and extent.
- Magnetic resonance imaging (MRI). A computerized magnetic scan of body tissues can more accurately determine the site and extent of the tumor.
- Lumbar puncture (spinal tap). This is done in cases where the tumor is near the spinal cord to see if the tumor has invaded the central nervous system.
- Blood tests. A complete blood count and blood chemistries test can help determine kidney, liver and bone marrow general function.
An accurate staging diagnosis is very important to effective treatment of the disease. After all tests are completed and the diagnosis has been made, a group of doctors including oncologists, radiologists, pathologists, and surgeons will determine the stage of the disease and the most effective treatment for it. The classification system used is as follows:
- Stage I. The tumor is found in the eye, head and/or neck, or near the sex organs, or near the liver or gallbladder, and has not spread to distant sites.
- Stage II. The tumor is located in the bladder/prostate, extremities (arms or legs), cranial paramenigeal, or the trunk. It is smaller than 2 inches (5 cm) and has not spread to the lymph nodes.
- Stage III. The tumor is located in the bladder/prostate, extremities (arms or legs), cranial paramenigeal, or the trunk. It is larger than 2 inches (5 cm) and may have spread to the lymph nodes.
- Stage IV. The tumor has spread to distant sites and it is found in more than one place at the time of diagnosis.
How is rhabdomyosarcoma treated?
Histology, or the way the tumor looks under the microscope, is also used to decide the extent of treatment. Unfavorable histology requires more intense treatment as the likelihood of reoccurrence is higher than it is with favorable histology. The type of treatment your child receives will depend on the stage of the disease. Usually rhabdomyosarcoma is treated with a combination of surgery, chemotherapy, and/or radiation therapy.
A treatment plan will be mapped out and explained to you in detail. The treatment given to your child will be done as an outpatient in the oncology clinic as much as possible; some patients, however, need hospitalization to closely monitor the chemotherapy infusion and its potential side effects.
Often, tumor resection (removal) is not possible at diagnosis. Chemotherapy may be used to shrink the tumor before surgery, allowing for surgery that is less extensive later. Radiation therapy is used for some patients to shrink the tumor area as well.
During the course of therapy and after the treatment is completed, various follow-up studies such as x-rays, CT scans and blood tests will be done to closely monitor your child's disease status.
Stem cell transplant is another treatment option for children diagnosed with metastatic rhabdomyosarcoma. The goal of this treatment is to maximize the dosages of chemotherapeutic agents used against the tumor cells. These higher dosages of chemotherapy also destroy the normal bone marrow cells, prohibiting their recovery. Bone marrow is responsible for the production of immature stem cells that grow into blood cells the body needs including red blood cells, white blood cells, platelets, plasma cells and other important cells. The bone marrow is restored to the child by using his or her own stem cells that are removed and saved before the chemotherapy is given allowing the return of normal bone marrow function.
What research is currently underway?
Current research in rhabdomyosarcoma is focusing on learning about the biology of this type of cancer and how this biology can predict how the cancer will respond to treatment. New drugs are being studied that are used in combination with standard drugs. New types of scans that assess how the tumor responds to treatment are also being studied.
About treatment for rhabdomyosarcoma at Children's
Children's cancer and blood disorders program consistently achieves treatment results ranking it as one of the top 10 programs in the U.S. Children's treats the majority of children with cancer and blood disorders in Minnesota and provides patients with access to a variety of clinical trials of ground-breaking new treatments. Through our renowned solid tumors program, patients experience unparalleled family support, a nationally renowned pain management team, and compassionate, coordinated care.
If you are a family member looking for a Children's hematologist or oncologist or wanting to schedule an appointment, please call our clinic at Children's – Minneapolis at (612) 813-5940.
If you are a health professional looking for consultation or referral information, please call Children's Physician Access at 1-866-755-2121 (toll-free) and ask for the on-call hematologist/oncologist.