Diagnosis of soft tissue sarcoma

Diagnosis is the process of finding out the cause of a health problem. Diagnosing soft tissue sarcoma can begin with a visit to a doctor, often a specialist. Your doctor will ask you about any symptoms you have and may do a physical exam. The doctor may order tests to check for soft tissue sarcoma or other health problems. But sometimes soft tissue sarcomas are found by chance (incidentally) while checking for a different health problem.

The process of diagnosis may seem long and frustrating. It’s normal to worry, but try to remember that other health conditions can cause similar symptoms as soft tissue sarcoma. It’s important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of soft tissue sarcoma.

The following tests are usually used to rule out or diagnose soft tissue sarcoma. Many of the same tests used to diagnose cancer are used to find out how far the cancer has spread (the extent of the cancer). Your doctor may also order other tests to check your general health and to help plan your treatment.

Health history and physical exam

Your health history is a record of your symptoms, risks and all the medical events and problems you have had in the past. Your doctor may ask about:

  • signs or symptoms that suggest soft tissue sarcoma, such as a lump or swelling
  • your history of cancer and if you have had radiation therapy or chemotherapy
  • chronic lymphedema
  • certain inherited conditions that you or family members have, such as neurofibromatosis type 1
  • your family history of soft tissue sarcoma and other cancers

A physical exam allows your doctor to look for any signs of soft tissue sarcoma. During a physical exam, your doctor may:

  • examine any lumps on your body, including checking their size and shape and how they feel
  • check how certain parts of your body are moving, such as your arms and legs, and if there is any weakness
  • examine the lungs
  • feel the abdomen for an enlarged liver or abnormalities

Find out more about a physical exam.

Complete blood count (CBC) and blood clotting tests

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check your general health, often before a biopsy.

Blood clotting (coagulation) tests check if your blood is clotting properly. Prothrombin time (PT), partial thromboplastin time (PTT) and international normalized ratio (INR) are common blood clotting tests. They are usually checked before a biopsy is done.

Find out more about a complete blood count (CBC).

Blood chemistry tests

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working and can help find abnormalities. The blood chemistry tests used often depend on the type of symptoms present. Blood chemistry tests that may be used include an electrolyte panel, liver function tests and kidney function tests.

Find out more about blood chemistry tests.


Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

An MRI is commonly used to examine a lump that doctors think may be a soft tissue sarcoma. It is often the first imaging test done for lumps in the arms or legs. An MRI can check the size of a tumour, what tissues and areas are nearby and if it has spread to other parts of the body.

Find out more about an MRI.

CT scan

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.

A CT scan is commonly used to examine a lump in a specific area, including checking its size and finding out what tissues and areas are nearby. It is often used to check the abdomen, back of the abdomen (retroperitoneum) and chest. If soft tissue sarcoma is diagnosed, a CT scan can be used to check if the cancer has spread to other parts of the body. A CT scan may be used instead of an MRI.

Find out more about a CT scan.


An x-ray uses small doses of radiation to make an image of parts of the body on film. It may be used to examine a lump.

Find out more about x-rays.


An ultrasound uses high-frequency sound waves to make images of parts of the body. It may be used to find out if a lump is a fluid-filled cyst or a solid tumour.

Find out more about an ultrasound.


During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from the pathologist will show whether or not cancer cells are found in the sample. If cancer is diagnosed, the report will also show the type of cancer and grade of the tumour. All of this is often done at a large cancer centre that is experienced in managing soft tissue sarcoma. It may take a few weeks to get the results.

The type of biopsy used depends on where the lump is and its size.

Core biopsy (also called core needle biopsy) uses a hollow needle to remove tissue from the body. It is a common type of biopsy used to diagnose soft tissue tumours. An imaging test, such as a CT scan, may be used to guide the needle to the tumour. Find out more about a core biopsy.

Surgical biopsy removes tissue from a lump or removes an entire lump during surgery. It is a common type of biopsy used to diagnose soft tissue tumours. Find out more about a surgical biopsy.

Endoscopic biopsy removes tissue from a lump or removes an entire lump during an endoscopy. It may be done when the lump is deep within the body.

Find out more about a biopsy.

Bone scan

A bone scan uses bone-seeking radioactive materials called radiopharmaceuticals and a computer to create a picture of the bones. It is used to check if the soft tissue sarcoma has spread to the bone.

Find out more about a bone scan.

Questions to ask your healthcare team

To make the decisions that are right for you, ask your healthcare team questions about a diagnosis.

Expert review and references

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

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