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 may 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 spread of rhabdomyosarcoma to lymph nodes, bone, lung, or beyond. These children mistakenly may be thought to have leukemia until biopsy results show the real diagnosis (see Biopsy Methods).

Many of the signs and symptoms listed are more likely to be caused by something other than rhabdomyosarcoma. Still, if your child has any of these symptoms, consult a 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 want to take a complete medical history to check for symptoms. A physical exam can provide information about 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 and/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 have 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 tumor that is thought to have spread to the lungs, although they wouldn't be needed if a chest CT scan is being done.

CT or CAT (computed tomography) scan: This test can give your child's doctor 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.

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.

Your child may be asked to drink a contrast solution and/or receive an IV (intravenous) line through which a contrast dye is injected. This helps better outline structures in the body. A second set of pictures is then taken.

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. Your child will need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. Some people feel a bit confined by the ring they have to lie in while the pictures are being taken. Newer CT equipment has been developed that is more open and patients feel less confined. In some cases, your child may need to be sedated before the test to minimize movement and help make sure the pictures come out well.

In recent years, spiral CT (also known as helical CT) has become 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 biggest advantage may be that the "slices" it images are thinner, which yields more detailed pictures and allows doctors to look at suspicious areas from different angles.

Magnetic resonance imaging (MRI) scan: This test may be used instead of a CT scan to look at the original rhabdomyosarcoma 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.

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 see details.

MRI scans are a little more uncomfortable than CT scans. First, they take longer -- often up to an hour. Second, your child has to lie inside a narrow tube, which can be confining. The machine also makes buzzing and clicking noises that may be disturbing. This means the child might need to be sedated before testing.

Bone scan: A bone scan can help show if a cancer has metastasized (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 (intravenously, or 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 show up -- that is, they attract the radioactivity. These areas may suggest cancer is present, but other bone diseases can also cause the same pattern. To distinguish between these conditions, other imaging tests such as plain x-rays or MRI scans, or even a bone biopsy might be needed.

Positron emission tomography (PET) scan: PET scans involve injecting glucose (a form of sugar) that contains a radioactive atom into the blood. The amount of radioactivity used is very low. Because cancer cells in the body are growing rapidly, they absorb large amounts of the radioactive sugar. A special camera can then create a picture of areas of radioactivity in the body. The picture 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.

PET scans are not used routinely in diagnosing rhabdomyosarcoma, but they can sometimes be very helpful in finding out if other lesions seen on the bone scan or CT scans are tumors. They are also very helpful in tracking how the patient is responding to the treatments.

Biopsy methods

In order to tell whether 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 are 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 rather large needle that can be inserted directly into a mass to withdraw a piece of tissue (core sample) about 1/16-inch across. 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 needle, and is quick and less uncomfortable. 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, expertise, 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 of rhabdomyosarcoma is made, as it is important to know if the tumor has spread to the bone marrow.

Bone marrow samples are obtained from a bone marrow aspiration and biopsy - two tests that are usually done at the same time. The samples are usually taken from the back of both of the pelvic (hip) bones.

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

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 area, the skin over the hip and the surface of the bone are numbed with local anesthetic, which may cause a brief stinging or burning sensation. 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. Even with the anesthetic, most patients still have some brief pain when the marrow is removed.

A bone marrow biopsy is usually done just after the aspiration. A small piece of bone and marrow (about 1/16 inch in diameter and 1/2 inch long) 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.

Examining and testing the biopsy samples

The biopsy samples will first be looked at under a microscope by a pathologist, who will 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. Most cases, however, will need other tests to process and look at the sample.

Pathologists may rely on special stains to identify the type of tumor. This technique uses special proteins (antibodies) that specifically attach to substances in rhabdomyosarcoma cells but not other cancers. When they attach to rhabdomyosarcoma cells they 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 rearrangements that were discussed earlier.

Once a diagnosis of rhabdomyosarcoma has been made, the pathologist will determine which kind of rhabdomyosarcoma your child has. This is important because it affects how the child is treated. Alveolar rhabdomyosarcoma, which tends to be more aggressive, requires more intensive treatment than embryonal rhabdomyosarcoma. Two sub-types of embryonal rhabdomyosarcoma (spindle cell and botryoid) both have a somewhat better prognosis than the usual form of embryonal rhabdomyosarcoma.

Finally, once the type of tumor has been identified, doctors need to assess, as accurately as possible, how much of it there is and where it has spread. The answers to "how much" and "where" are expressed in a kind of shorthand known as staging. This information, along with the type of tumor, will help determine the best treatment for the child.