Diagnosing soft tissue sarcoma

To diagnose a sarcoma, a specialist doctor will usually arrange for you to have use an ultrasound scan and a biopsy.

How soft tissue sarcoma is diagnosed

If you have symptoms of soft tissue sarcoma, you usually start by seeing your GP, who will examine you. They may arrange for you to have tests, such as an ultrasound of the lump.

If they are not sure what the problem is, or think your symptoms could be caused by cancer, they will refer you to a specialist doctor.

If your GP thinks you might have a sarcoma, you will usually be seen at the hospital within 2 weeks.

The specialist doctor will ask about your symptoms and your general health. They will also examine you. This includes feeling the area where there is pain or swelling. You may need to have blood tests and a chest x-ray to check your general health.

The following tests are commonly used to diagnose a soft tissue sarcoma. The tests you have will depend on the part of the body being investigated.

Our cancer support specialists or your specialist doctor or nurse can give you information about any tests we do not explain here.

Waiting for test results can be a difficult time. It may take from a few days to a couple of weeks for the results of your tests to be ready.

Ultrasound scan

An ultrasound uses soundwaves to make a picture of the inside of the body. If you have a lump in your tummy (abdominal lump), you may have an abdominal ultrasound.

If the lump is in the womb, the ultrasound device may also be gently inserted into the vagina. This is called a trans-vaginal ultrasound scan.

If the lump is in a limb, you may also have an ultrasound scan of the area.


A biopsy means the doctor takes a sample of cells or tissue from a lump to be checked for cancer under the microscope. It is the only way to tell whether the lump is a cancerous (malignant) or non-cancerous (benign) tumour.

If a biopsy shows sarcoma, your doctors may do further tests on the sample to try to find out exactly what type of sarcoma it is. This is called cytogenetic testing.

There are different ways of doing a biopsy.

  • Fine needle aspiration (FNA) biopsy

    Your doctor uses a very thin needle and a syringe to withdraw small pieces of tissue from the lump. They can often guide the needle to the right place by feeling the lump near the surface of the body. If they cannot feel the lump, or if it is deep inside the body, they may use an ultrasound or a CT scan to guide the needle.

    An FNA may be slightly uncomfortable, but should not be painful. You may have a local anaesthetic injection to numb the area before the biopsy is taken.

    Sometimes an FNA does not provide enough cells to give a clear diagnosis and a different biopsy is needed.

  • Core needle biopsy

    This is similar to an FNA, but the doctor uses a bigger needle. Before the biopsy, you have a local anaesthetic injection in the skin around the lump to numb it. The doctor then passes the biopsy needle through the skin and into the lump to take the sample. They use a special needle to do this. They may take several samples.

    Sometimes the doctor uses an ultrasound or a CT scan to guide the needle to the right place.

    You are usually awake during a core needle biopsy, although you may be given a sedative to make you feel more relaxed and drowsy. Sometimes the biopsy is done under a general anaesthetic, particularly for children.

    For most people, a core needle biopsy shows whether the lump is cancerous (malignant) or non-cancerous (benign). But sometimes it does not provide enough cells to give a clear diagnosis. If this happens, you will need a surgical biopsy.

  • Surgical biopsy

    This type of biopsy is done less often. It may be useful if the results of a needle biopsy are unclear, or if the lump is deep inside the body.

    The surgeon uses a surgical knife (scalpel) to open the affected area and remove a sample from the lump. This is called an incision biopsy. Sometimes, if the lump is small, the doctor removes the whole lump. This is called an excision biopsy.

    You will be given a local or a general anaesthetic before a surgical biopsy. This depends on your general health, the size of the tumour and how deep it is inside the body.

If you are going to have surgery to remove the tumour, you may not have a biopsy taken before your operation. Instead, the whole tumour is sent to the laboratory after the operation for tests to confirm that it is a sarcoma.

Further tests

If the tests show that you have a soft tissue sarcoma, your doctor may do further tests. These are to find out the size and position of the cancer and whether it has spread to other parts of the body. This is called staging. It helps you and your doctor decide on the best treatment for you.

  • Chest x-ray

    You may have a chest x-ray to check your general health and to look for any sign that the cancer has spread to your lungs. This is because the lungs are one of the most common places for soft tissue sarcomas to spread to.

  • MRI scan

    An MRI scan uses magnetism to build up a detailed picture of areas of your body.

  • CT scan

    A CT scan takes a series of x-rays, which build up a 3D picture of the inside of the body.

  • PET scan

    A PET scan uses low-dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body.