If you have symptoms or other reasons that suggest you may have a sarcoma, the doctor will use one or more methods to find out if the disease is really present.

Signs and symptoms of soft tissue sarcomas

When sarcomas develop on the arms or legs, most people simply notice a lump that has grown over a period of time (weeks to months). Although it can be painful, generally, it doesn't hurt. More than half of sarcomas begin in an arm or leg.

When sarcomas grow in the retroperitoneum (the back wall inside the abdomen), the symptoms they cause are more often caused by other problems. Sometimes the tumors cause pain. They may also cause blockage or bleeding of the stomach or bowels. They may grow large enough for the tumor to be felt in the abdomen. About 20% of sarcomas will begin in the abdomen (stomach) area.

Sarcomas can also begin on the outside of the chest or abdomen (about 10%) or in the head or neck area (around 10%).

If you have any of the following problems, see a doctor right away:

• a new lump or a lump that is growing anywhere on your body
• abdominal pain that is getting worse
• blood in your stool or vomit
• black, tarry stools (when bleeding happens in the stomach or bowels, the blood isn't always red, and it may make the stool look very black and tarry)

Since symptoms of soft tissue sarcomas often do not appear until the disease is advanced, only about 50% of soft tissue sarcomas are found in the early stages, before they have spread.

Medical history and physical exam

Your doctor will take a complete medical history to check for any risk factors and to ask you about symptoms, as well as any other medical conditions. They will also physically examine you to look for signs of sarcomas and other health problems.

Biopsy

A biopsy is a test where a sample of tissue is removed from a tumor to see if it is a type of cancer. The piece of tissue is looked at under a microscope and, some other tests may be done on the sample as well. Although a physical exam may suggest that a tumor is a sarcoma, a biopsy is the only way to be certain that it is a sarcoma and not another type of cancer or a benign disease

Grading

If a sarcoma is present, the biopsy will determine what type it is and its grade. The grade of a sarcoma is based on the way the cancer looks under the microscope. In grading a cancer, the pathologist (doctor who specializes in diagnosing cancer microscopically) will consider factors such as how closely the tumor resembles normal tissue and how many of the cells appear to be dividing.

The sarcomas with cells looking more normal and with fewer cells dividing are generally placed in a low-grade category. Low-grade tumors are slow growing, slower to spread, and often have a better outlook than higher-grade tumors. Although the grade is usually based on the way the cells look and how many are dividing, certain types of sarcoma are automatically considered a certain grade. For example, myxoid liposarcoma and dermatofibrosarcoma protuberans are always considered to be low grade. On the other hand, synovial sarcoma and alveolar soft-part sarcoma are always high grade.

The grading system used most often by doctors who treat patients with sarcoma divides sarcomas into 2 categories: low grade or high grade. The official staging system (see the section, "How are soft tissue sarcomas staged?") actually divides sarcomas into 4 grades (1to 4) but then combines the 2 lowest into low-grade and the 2 highest into high-grade categories. The grade of a sarcoma is valuable in predicting how rapidly it will grow and spread and also in determining a patient's outlook (prognosis). The grade is part of what is used to determine the stage of a sarcoma.

Several types of biopsies may be used in diagnosing sarcomas. Doctors with experience in these tumors will choose one, based on the size and location of the tumor. Most experts prefer a fine needle aspiration or a core needle biopsy as the first step.

Fine needle aspiration (FNA) biopsy:

In FNA, the doctor uses a very thin needle and a syringe to withdraw small fragments of tissue from the tumor mass. The doctor can often aim the needle while feeling a mass near the surface of the body. If the tumor is too deep to feel, the doctor can guide the needle while viewing a computed tomography (CT) scan. The main advantage of FNA is that it can be used to biopsy tumors deep in the body without surgery. The disadvantage is that the thin needle may not remove enough tissue to make a precise diagnosis.

FNA is often useful in showing that a mass first thought to be a sarcoma (found on physical exam or imaging tests) is really another type of cancer, a benign tumor, an infection, or some other disease. But if FNA results suggest a sarcoma, another type of biopsy will usually follow to remove enough tissue to confirm that diagnosis. After a sarcoma is diagnosed, FNA is most useful in determining whether additional tumors in other organs are metastases.

Core needle biopsy

Core needle biopsies use a needle that is larger than the FNA needle. Sometimes this needle is called a Tru-Cut needle. It removes a cylindrical piece of tissue about 1/16 inch across and 1/2 inch long. It usually removes enough tissue to see if a sarcoma is present. As with the FNA, CT scans can be used to guide the needle into tumors of internal organs.

Excisional or incisional biopsy

For an excisional biopsy, the surgeon removes the entire tumor. In an incisional biopsy, only a piece of a large tumor is removed. This method almost always provides enough tissue to make a diagnosis of the exact type and grade of sarcoma. If the tumor is near the skin surface, this is a simple operation that can be done with local or regional anesthesia (numbing medication given near the mass or into a nerve). But if the tumor is deep inside the body, general anesthesia is used (the patient is asleep).

Proper biopsy technique is a very important part of successful treatment of soft tissue sarcomas. An improper biopsy may lead to tumor spread and problems removing the tumor later on. To prevent these problems, these 2 types of biopsies should only be performed by a surgeon with experience in treating sarcomas. An incisional biopsy in the wrong place or an excision without wide enough margins can make it harder to completely remove a sarcoma without causing too much damage to that part of the body.

If a tumor is rather small, near the surface of the body, and not located near critical tissues (such as important nerves or large blood vessels), the doctor may choose to remove the entire mass and a margin of normal tissue in an excisional biopsy. This surgery combines the biopsy and the treatment into one operation.

If the tumor is large, then an incisional biopsy is needed. A surgeon experienced in sarcoma treatment should perform this procedure. The incision needs to be planned so that the resulting wound can be completely removed later on as part of a wide excision.

Special testing of biopsy samples

Sometimes special tests ( immunohistochemistry tests) are needed to accurately determine whether a sarcoma is present and, if so, what type. Part of the biopsy sample is treated with special laboratory antibodies that recognize cell proteins typical of certain kinds of sarcomas. The cells are treated with chemicals that cause the cells containing the specific proteins to change color. The color change is then seen under a microscope.

In cytogenetics, cells are examined with a microscope to see if part of one chromosome is abnormally attached to part of a different chromosome, as happens in certain types of sarcomas. To see the chromosomes clearly, the malignant cells usually must be grown in laboratory flasks for at least a week.

Fluorescent in situ hybridization (FISH) can sometimes be used to detect chromosome changes without first growing the cells in the lab. Although tests of chromosome changes are not required to diagnose most sarcomas, they are sometimes very useful. And as new changes are discovered, these tests may become more important and more common.

Imaging tests

These may be done before a biopsy in certain cases, but often are done once a diagnosis of sarcoma is made.

Chest x-ray

This test may be done to determine whether the sarcoma has spread to your lungs.

Magnetic resonance imaging scans

Magnetic resonance imaging (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 tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of the body. A contrast material might be injected, just as with CT scans, but is used less often.

MRI scans are often part of the work-up of any tumor that could be a sarcoma. They are often better than CT scans in evaluating sarcomas in the arms or legs. They provide a good picture of the extent of the tumor. They can tell your health care team many things about the tumor, including location, size, and sometimes even the type of tissue it comes from (like fat or muscle). This makes MRI scans useful in planning a biopsy.

MRIs are also very helpful in examining the brain and spinal cord.

MRI scans are a little more uncomfortable than CT scans. First, they take longer -- often up to an hour. Also, you have to lie inside a tube, which is confining and can be upsetting. The machine also makes a thumping noise that you may find disturbing. Some places will provide headphones with music to block this noise out.

Ultrasound

Ultrasound uses sound waves and their echoes to produce pictures of parts of the body. A small instrument called a transducer emits sound waves and picks up the echoes as they bounce off the organs. The sound wave echoes are converted by a computer into an image that is displayed on a computer screen.

This is a very easy procedure. It uses no radiation, which is why it is often used to look at developing fetuses. For most ultrasounds, you simply lie on a table while a technician moves the transducer over the part of your body being examined. Usually, the skin is first lubricated with gel. This test may be done before a biopsy to see if the lump is a cyst, meaning it contains fluid and is likely benign, or is solid and more likely a tumor. This test is often not needed if an MRI was done.

Computed tomography scan

The computed tomography (CT) scan is an x-ray procedure that produces detailed, cross-sectional images of your body. Instead of taking one picture like a conventional x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body. The machine will create multiple images of the part of your body that is being studied. A CT scan is often done if the doctor suspects a soft tissue sarcoma in the chest, abdomen, or the retroperitoneum. This test can help tell if your sarcoma has spread into your liver or other organs.

You may be asked to drink 1 to 2 pints of a solution of contrast material before the scan. This helps outline the intestine so that it is not mistaken for tumors.

Often after the first set of pictures is taken you will receive an intravenous (IV; into a vein) injection of a dye or radiocontrast agent that helps better outline structures in your body. A second set of pictures is then taken.

The IV injection of contrast dye can also cause some flushing (redness and warm feeling). Some people are allergic and get hives or, rarely, more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays. You will need to lie still on a table, and the part of your body being examined is placed within the scanner, a doughnut-shaped machine that completely surrounds the table. Most scans only take a few minutes.

CT scans might be done to precisely guide a biopsy needle into a tumor that is inside the body – the chest or abdomen, for example. For this procedure, called a CT-guided needle biopsy, the patient remains on the CT scanning table while a radiologist advances a biopsy needle toward the location of the mass. CT scans are repeated until the doctors are confident that the needle is within the mass.

Positron emission tomography scan

In this test, radioactive glucose (sugar) is injected into the patient's vein to look for cancer cells. Because cancers use glucose (sugar) at a higher rate than normal tissues, the radioactivity will tend to concentrate in the cancer. A scanner can spot the radioactive deposits. A positron emission tomography (PET) scan is useful when your doctor thinks the cancer has spread but doesn't know where. A PET scan can be used instead of several different x-rays because it scans your whole body. Its use in sarcomas is still new, but this technique can be helpful in distinguishing malignant tumors from benign ones. So far it hasn't been used to routinely evaluate patients with sarcomas.

Last Medical Review: 03/03/2009
Last Revised: 05/14/2009