Sarcoma Diagnosis and Staging

January 22, 2026

This page was reviewed under our medical and editorial policy by Lee Cranmer, M.D., Ph.D., professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Sarcomas are uncommon cancers that start in the body’s soft tissues or bones. They account for about 1% of adult cancer diagnoses and 15% of childhood cancers.

There are no screening tests for early diagnosis of these conditions. Usually, when a patient begins experiencing sarcoma symptoms, the search for a diagnosis begins.

For soft tissue sarcomas, people often have a painless mass that they bring to their doctor’s attention. For bone sarcomas, bone pain,swelling, or even an unexpected fracture are more common.

How Is Sarcoma Diagnosed?

A variety of imaging, laboratory and procedural tests may be used as part of the sarcoma diagnostic process.

The care team may use the following tests to look for sarcomas.

History and physical examination: The doctor examines the patient for signs of disease, such as a lump or mass. He or she may also ask questions about the patient’s medical history. These assessments help the doctor understand the extent of the problem and how it is impacting a patient’s life. The doctor may then use this information to develop a plan for diagnosis and treatment.

Sarcoma blood test: There is no specific test of the blood to diagnose sarcoma. However, blood tests are important in assessing the function of a patient’s organs and monitoring the progress of treatment. Such tests are especially important for ensuring a patient’s safety. Blood tests that may be performed include a complete blood count (CBC) to measure levels of red blood cells, white blood cells, hemoglobin (an oxygen-carrying protein) and platelets in the blood; and blood chemistry studies to assess the function of a patient’s organs, such as the liver and kidney. Many other blood tests may be ordered by the care team based on the specific questions that need to be answered for optimal care.

Bone scan: This imaging test may be the first test a doctor performs if a bone tumor is suspected. The test may be done at a hospital or other medical facility. The patient receives a dose intravenously (through a vein) of a medicine that goes to areas where the bone may be involved by cancer. This medicine emits X-rays that may be detected by a special machine and turned into images. If the images indicate bone sarcoma may be present, other tests are used to confirm the patient’s diagnosis.

Sarcoma biopsy: The way sarcoma and other cancers are diagnosed is through a biopsy. In a biopsy, a piece of tissue that’s thought to be of concern is obtained. There are a number of ways to do this, including by using a needle along with some type of imaging to guide the needle to a tumor site, doing surgery to obtain a sample, or sometimes doing blood tests that may be used for diagnosis. This specimen is then examined in the laboratory to determine what it is. This examination is typically done by a pathologist. Biopsies are used to confirm a diagnosis of sarcoma and to learn more about the sarcoma cancer that may help with treatment.

CT or CAT (computed tomography) scan: This test involves taking a series of X-ray images to form a computer-generated image, which determines tumor size, location and spread. Special dyes (called “contrast”) may be given intravenously (into a vein) or by mouth to make more useful images.

MRI (magnetic resonance imaging) scan: This procedure uses radio waves and strong magnets to produce detailed images of the body’s tissues, including tumor size and location. The images may also provide information about the chemical makeup of a tumor.

PET (positron emission tomography) scan: For this test, a small amount of radioactive sugar is injected into the bloodstream, followed by a radioactivity scan to detect cancer cells (which takes up sugar at a faster rate than normal cells).

FISH (fluorescence in situ hybridization): This is a laboratory test that looks for genetic or chromosomal changes in the DNA of biopsied cells. This information may be used to guide treatment.

Immunohistochemistry: This is a laboratory test that looks for the presence of certain proteins on biopsied cells or sarcoma tissue samples. This may be very helpful in many ways. It may help determine what the exact diagnosis is. It may also be used to determine if certain treatments may be helpful or not for a given patient. This test is performed by a pathologist.

Sarcoma Stages

Based on the results of all these tests and history and physical examination, the medical team will then “stage” the sarcoma cancer. Determining the stage of the cancer helps in making decisions about treatment that might be useful and about the likelihood of success of treatment. In this way, determining the stage may be very helpful to the care team and to the patient in making decisions about medical care. Generally, cancer detected in earlier stages has better outcomes than that cancer detected in more advanced stages.

Sarcomas are assigned a number from 1 to 4 to indicate the stage. The lower the stage number, the less the cancer has spread in the body. The specific staging criteria, or rules, depend on the sarcoma type. For example, sarcomas on the extremities (arms or legs) are staged differently than sarcomas that may occur inside the abdomen (or “retroperitoneum”).

The American Joint Committee on Cancer (AJCC) TNM staging system is the one that is most often used to determine the sarcoma stage. While there are some variations, the systems of the AJCC for sarcomas generally use the four factors listed below.

T (tumor): The extent and size of the primary sarcoma tumor (the first tumor where the cancer arose).

N (node): Whether cancer has spread to nearby lymph nodes. For example, if a sarcoma started on the right arm, the lymph nodes in the right armpit/axilla would be viewed as in the same region of the body.

M (metastasis): If the cancer has spread to distant areas of the body, like the lungs or other bones. Generally, the sarcoma gets to a distant site through the blood.

G (grade): How abnormal the cancer cells look when examined under a microscope by a pathologist (a doctor specializing in laboratory medicine). Sarcoma grade generally is done on a three-point scale, 1 (low), 2 (intermediate), or 3 (high). Sarcomas with a higher grade grow more quickly and are more likely to spread to other parts of the body than lower-grade tumors. A number or level is assigned to each of these four factors. The combined information of all four factors is then used to determine the stage of the sarcoma affecting a person.

Learn more about the bone cancer stages

Learn more about the soft tissue sarcoma stages

Learn about stage 4 metastatic sarcoma

Sarcoma Screening

There are currently no screening guidelines for sarcomas, since no screenings have been shown to lower risk of dying for people of average risk. However, the patient’s physician may recommend more vigorous monitoring if the patient is at a high risk of developing a sarcoma. These factors may include:

• Patients who have had a prior sarcoma.
• Previous cancer therapy with chemotherapy or radiation, especially when someone was a child.
• Genetic conditions that increase sarcoma risk
• Family history of sarcoma
• Certain exposures, such as exposure to herbicides.