Certain signs and symptoms might suggest that a person may have rhabdomyosarcoma, but tests are typically needed to confirm the diagnosis.

Signs and symptoms of rhabdomyosarcoma

The location of the tumor largely determines the problem that brings the mass to someone's attention:

• When the tumor is in the trunk, extremities, or groin, the first sign is usually a mass or swelling that often doesn't cause any pain or other problems.
• Tumors around the eye cause the eye to bulge or the child to appear to be cross-eyed.
• When it is in the ear or nasal sinuses, rhabdomyosarcoma can mimic an earache or a sinus infection.
• Tumors in the bladder and vagina may bleed or grow big enough to make it difficult or painful to urinate or have bowel movements.
• Tumors in the abdomen or pelvis can cause vomiting, abdominal pain, or constipation.
• Rhabdomyosarcoma rarely develops in the bile ducts, but when it does it can cause yellowing of the eyes or skin.

It is unusual for children to come to the doctor with symptoms related to spread or metastasis from rhabdomyosarcoma, but occasionally enlarged lymph nodes, bone pain, chronic cough, or weakness and weight loss will signal the spread of rhabdomyosarcoma. These children may be thought to have leukemia until biopsy results show the real diagnosis (see "Biopsy methods").

Many of these signs and symptoms are more likely to be caused by something other than rhabdomyosarcoma. Still, if your child has any of these symptoms, check with your doctor so that the cause can be evaluated and treated, if needed.

Medical history and physical exam

If your child has any signs or symptoms that may suggest rhabdomyosarcoma, the doctor will take a complete medical history to check for symptoms. The doctor will also physically examine your child to look for signs of rhabdomyosarcoma and other health problems. For example, the doctor may be able to see or feel an abnormal mass in the body.

If symptoms or the results of the physical exam suggest rhabdomyosarcoma might be present, other tests probably will be done. These might include imaging tests, biopsies, and/or lab tests.

Imaging tests

Imaging tests use x-rays, magnetic fields, or radioactive substances to create pictures of the inside of the body. Imaging tests may be done for a number of reasons, including to help find out whether a suspicious area might be cancerous, to learn how far cancer may have spread, and to help determine if treatment has been successful. Most patients who have or may have cancer will get one or more of these tests.

Plain x-rays

These are sometimes used to look for tumors, although their use is fairly limited outside of looking at bones. They are sometimes done to look for cancer that might have spread to the lungs, although they wouldn't be needed if a chest CT scan is being done.

Computed tomography (CT) scan

The CT scan is an x-ray test that produces detailed cross-sectional images of parts of your child's body. Instead of taking one picture, like a regular x-ray, a CT scanner takes many pictures as it rotates around your child while he or she lies on a table. A computer then combines these pictures into images of slices of the part of the body being studied. Unlike a regular x-ray, a CT scan creates detailed images of the soft tissues in the body.

This test can provide fairly detailed information about a tumor, including how large it is and whether or not it has invaded nearby structures. It can also be used to look at nearby lymph nodes, as well as the lungs or other areas of the body where the cancer may have spread.

Before the scan, your child may be asked to drink a contrast solution and/or get an intravenous (IV) injection of a contrast dye that helps better outline abnormal areas in the body. Your child may need an IV line through which the contrast dye is injected. The contrast may cause some flushing (a feeling of warmth, especially in the face). Some people are allergic and get hives. Rarely, more serious reactions like trouble breathing or low blood pressure can occur. Be sure to tell the doctor if your child has ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. Your child will need to lie still on a table while this is being done. Younger children may be given medicine to help keep them calm or even asleep during the test.

Spiral CT (also known as helical CT) is now available in many medical centers. This type of CT scan uses a faster machine. The scanner part of the machine rotates around the body continuously, allowing doctors to collect the images much more quickly than with a standard CT. This lowers the chance of blurred images occurring as a result of breathing motion. It also lowers the dose of radiation received during the test. The slices it images are thinner, which yields more detailed pictures.

Magnetic resonance imaging (MRI) scan

Like CT scans, MRI scans give detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of parts of the body. A contrast material called gadolinium may be injected into a vein before the scan to better show details. The contrast material usually does not cause allergic reactions.

This test may be used instead of a CT scan to look at the tumor and the tissues around it. MRI is also very useful if your child's doctor is concerned about possible spread to the spinal cord or brain.

MRI scans take longer than CT scans, often up to an hour. Your child may have to lie inside a narrow tube, which is confining and can be distressing, so sedation is sometimes needed. Newer, more open MRI machines may be another option. The MRI machine makes loud buzzing and clicking noises that your child may find disturbing. Some places provide headphones or earplugs to help block this noise out.

Bone scan

A bone scan can help show if a cancer has spread to the bones, and is often part of the workup for children with rhabdomyosarcoma. For this test, a small amount of low-level radioactive material is injected into a vein (IV). The substance settles in areas of damaged bone throughout the entire skeleton over the course of a couple of hours. Your child then lies on a table for about 30 minutes while a special camera detects the radioactivity and creates a picture of the skeleton.

Areas of active bone changes attract the radioactivity and show up on the scan. These areas may suggest cancer is present, but other bone diseases can also cause the same pattern. For an accurate diagnosis, other imaging tests such as plain x-rays or MRI scans, or even a bone biopsy might be needed.

Positron emission tomography (FDG-PET) scan

For a FDG-PET scan, fluorodeoxyglucose (FDG, a form of sugar) containing a radioactive atom is injected into the blood. The amount of radioactivity used is very low. Because cancer cells in the body are growing quickly, they absorb large amounts of the radioactive sugar. A special camera can then create a picture of areas of radioactivity in the body.

PET scans are not used routinely to diagnose rhabdomyosarcoma, but they can sometimes be very helpful in finding out if suspicious areas on bone scans or CT scans are tumors. They are also very helpful in tracking how the cancer is responding to the treatments. The picture from a PET scan is not finely detailed like a CT or MRI scan, but it provides helpful information about the whole body.

Some newer machines are able to perform both a PET and CT scan at the same time (PET/CT scan). This allows the doctor to compare areas of higher radioactivity on the PET with the appearance of that area on the CT.

Biopsy methods

In order to tell if a mass is cancer (and if so, what type), your child's doctor will need to have a piece of the tumor removed (biopsied) and looked at under a microscope. Usually several different kinds of tests are done on the sample to sort out what kind of tumor it is.

Biopsies can be done in several ways. Which approach is used will depend on where the mass is located, the age of the child, and the expertise and experience of the doctor doing the biopsy.

Surgical biopsy

The most common approach is to surgically remove a small piece of tumor while the child is under general anesthesia (asleep) and have it looked at by a pathologist (a doctor who specializes in diagnosing diseases from the results of lab tests). In some cases, nearby lymph nodes may also be removed and tested to see if the tumor has spread.

Needle biopsies

If for some reason a surgical biopsy cannot be done, a less invasive biopsy using a needle may be used. There are 2 kinds of needle biopsies, each of which has pros and cons.

Core needle biopsy: Core needle biopsies use a large, hollow needle that can be inserted directly into a mass to withdraw a piece of tissue (core sample). This core sample can be used for all the required tests. The advantages are no surgery, no incision, perhaps no general anesthesia, and less expense. On the negative side, the specimen is smaller, and the biopsy may miss the cancer and sample benign tissue only. If the specimen is not a good sample of the tumor, another biopsy will be necessary.

Fine needle aspiration (FNA) biopsy: This technique uses a very small hollow needle attached to a syringe to withdraw (aspirate) a small tumor sample. An FNA biopsy is ideally suited to tumors that are near the surface of the body and can be reached easily. The downside is that the sample is very, very small. Evaluation of these tiny samples requires that the pathologist be experienced with this technique and be able to decide which tests will be most helpful on a small sample. In cancer centers that have the experience, equipment, and knowledge to extract the most information from very small amounts of tissue, FNA can be a valuable -- though certainly not foolproof -- diagnostic approach.

Bone marrow aspiration and biopsy

These tests aren't used to diagnose rhabdomyosarcoma, but they may be done after the diagnosis to find out if the tumor has spread to the bone marrow. The 2 tests are usually done at the same time. The samples are usually taken from the back of both of the pelvic (hip) bones, although in some patients they may be taken from the sternum (breastbone) or other bones.

These tests may be done during the surgery to treat the main tumor (while the child is still under anesthesia), or they may be done as a separate procedure.

If the bone marrow aspiration is being done as a separate procedure, the child lies on a table (on his or her side or belly). After cleaning the skin over the hip, the doctor numbs the area and the surface of the bone with local anesthetic, which may cause a brief stinging or burning sensation. Even with the local anesthetic, most patients still have some brief pain when the marrow is removed. In some cases, the child is also given other medicines to reduce pain or may even be asleep during the procedure. A thin, hollow needle is then inserted into the bone, and a syringe is used to suck out a small amount of liquid bone marrow.

A bone marrow biopsy is usually done just after the aspiration. A small piece of bone and marrow is removed with a slightly larger needle that is twisted as it is pushed down into the bone. The biopsy may also cause some brief pain. Once the biopsy is done, pressure will be applied to the site to help stop any bleeding.

Lumbar puncture (spinal tap)

Lumbar puncture is not a common test for rhabdomyosarcoma, but it may be done for tumors in the head near the covering of the brain (the meninges). This test is used to look for cancer cells in the cerebrospinal fluid (CSF), which is the liquid that bathes the brain and spinal cord.

For this test, the doctor first numbs an area in the lower part of the back near the spine. The doctor may also recommend that the child be given something to make him or her sleep so the spinal tap can be done without difficulty or causing harm. A small, hollow needle is then placed between the bones of the spine to withdraw some of the fluid.

Lab tests on the biopsy samples

A pathologist will look at the biopsy samples under a microscope to try to determine if cancer cells are present. If the pathologist diagnoses cancer, the next step is to decide whether the cancer is a rhabdomyosarcoma. In rare cases, the pathologist can see that the cancer cells have small muscle striations (myofibrils), which confirm that the cancer is a rhabdomyosarcoma. But in most cases, other lab tests are needed to confirm the diagnosis.

Pathologists may use special stains on the samples to identify the type of tumor. The stains contain special proteins (antibodies) that specifically attach to substances in rhabdomyosarcoma cells but not other cancers. The stains produce a distinct color that can be seen under a microscope. This lets the pathologist know that the tumor is a rhabdomyosarcoma.

Sometimes the tumor will also be tested for genetic abnormalities. Genetic tests look for the translocations and other DNA changes such as those discussed in the section "Do we know what causes rhabdomyosarcoma?"

If a diagnosis of rhabdomyosarcoma is made, the pathologist will also use these tests to help determine which kind of rhabdomyosarcoma your child has. This is important because it affects how the child is treated. For example, alveolar rhabdomyosarcoma, which tends to be more aggressive, requires more intensive treatment than embryonal rhabdomyosarcoma.

Last Medical Review: 09/08/2009
Last Revised: 09/08/2009