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. About 60% of sarcomas begin in an extremity.

When sarcomas grow in the retroperitoneum (the back wall inside the abdomen), the symptoms they cause aren't very specific. About one third of the time they can cause pain. Sometimes they are found because they cause blockage or bleeding of the stomach or bowels. They can also be found because they have grown large enough to be felt in the abdomen. About 20% of sarcomas will begin here.

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 (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. He or she will also perform a physical exam to look for signs of sarcomas and other health problems.

Biopsy

This is usually the first test your doctor should perform if there is concern about a sarcoma. Some experts believe that any soft tissue tumor that is 2 inches or more in size and hasn’t gone away after a month or two should be biopsied. For a biopsy, the doctor removes a sample of tissue from the tumor for examination under a microscope and, in some cases, by other laboratory tests. Although there are many different ways to perform the biopsy, usually this is done with a large bore needle after numbing the area with local anesthesia. While a physical exam may suggest that a mass 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 noncancerous disease.

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. In addition to considering the way the cells look and how many are dividing, the type of sarcoma also influences its grade in some cases. 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 below) actually divides sarcomas into 4 grades (1-4) but then combines them into low-grade or 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 for survival (prognosis). The grade is used to determine the stage of a sarcoma (see How Are Soft Tissue Sarcomas Staged?).

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.

Types of Biopsy

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 does not require surgery. The disadvantage is that in many cases the thin needle cannot remove enough tissue to make the doctor certain that a sarcoma is present or to determine its exact type or grade.

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. 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 or Tru-cut biopsy: The needle used for this biopsy is larger than the FNA needle. It removes a cylindrical piece of tissue about 1/16 inch across and 1/2 inch long. In most cases, it removes enough tissue to see whether a sarcoma is present. As with the FNA, CT scans can be used to guide core or Tru-cut needles into tumors of internal organs.

Excisional or incisional biopsy: A surgeon cuts through the skin to remove the entire mass (excisional biopsy) or a small part of a large tumor (incisional biopsy). 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).

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 often chooses an excisional biopsy to remove the entire mass and a margin of normal tissue. This combines the diagnostic biopsy and surgical treatment into one operation.

Proper biopsy technique is a very important part of successful treatment of soft tissue sarcomas. An improper biopsy may lead to tumor spread. If the tumor is small, it can be completely removed with an excisional biopsy.

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

Special testing of biopsy samples: Sometimes special tests are needed to accurately determine whether a sarcoma is present and, if so, what type. Immunohistochemistry involves treating part of the biopsy sample 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.

Ultrasound: Ultrasound uses sound waves and their echoes to produce a picture of internal organs or masses. 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. When you have an ultrasound examination, you simply lie on a table, and a technician moves the transducer over the part of your body being examined. Usually, the skin is first lubricated with oil. This 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.

Computed tomography (CT): The 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. This test can help tell if your sarcoma has spread into your liver or other organs.

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.

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.

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. The test is painless, but you may find it uncomfortable to hold still in certain positions for minutes at a time.

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

Magnetic resonance imaging (MRI) scans: 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 particularly helpful in examining the brain and spinal cord. Many doctors also prefer them to CT scans in evaluating sarcomas. They provide a good picture of the extent of the tumor.

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 out.

Chest x-ray: This test may be done to determine whether the sarcoma has spread to your lungs.

Positron emission tomography (PET) scans: PET uses glucose (a form of sugar) that contains a radioactive atom. Cancer cells of the body absorb high amounts of the radioactive sugar because of their high rate of metabolism, and a special camera can detect the radioactivity. PET 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 in the routine evaluation of patients with sarcomas. Last Revised: 11/15/2006