Multiple Myeloma Diagnosis and Tests

Medically Reviewed by Melinda Ratini, MS, DO on May 27, 2023
4 min read

If your doctor thinks you may have multiple myeloma -- a cancer of the bone marrow -- you'll need tests. These may include blood, urine, imaging, and bone marrow tests. With multiple myeloma, cancerous plasma cells divide and grow inside your bone marrow. Plasma cells are white blood cells that produce antibodies. They're part of your immune system.

Doctors can learn a lot about what's going on by checking your blood:

  • Serum protein electrophoresis (SPEP): This measures immunoglobulins (antibodies) in your blood. Your body makes these when it's fighting off something. SPEP looks specifically for an abnormally high amount of an immunoglobulin known as the M protein. It's released by cancerous plasma cells called myeloma cells, and finding it in your blood can be the first step to diagnosing multiple myeloma. The lower your level of M protein, the less likely your cancer has spread.
  • Immunofixation, also called immunoelectrophoresis (IFE): If a problem protein is found by the SPEP test, your doctor may use this blood test to learn more about it. That can help you find out what type of immunoglobulins are involved with the myeloma.
  • Free light chains (FLC): Light chains make up antibodies in your blood. This test measures how many you have, which can help determine if you have myeloma.
  • Complete blood count (CBC): This measures the number of red blood cells, white blood cells, and platelets you have. It can tell your doctor if multiple myeloma is keeping you from making enough blood cells, and if so, how far off your count is.
  • Chemistry profile: This is a series of tests that shows your levels of things like calcium, sodium, and potassium. Multiple myeloma can cause an increase in calcium called hypercalcemia. The tests also check kidney and liver function.
  • Beta2-microglobulin (B2-M): This helps your doctor know how much B2-M, a protein made by cancer cells, is in your blood. Higher levels can be a sign of a more advanced stage of myeloma.
  • Quantitative immunoglobulins: These tests look for amounts of different types of immunoglobulins, or antibodies, in your blood. The multiple myeloma protein may be an IgG, IgA or, rarely, an IgD or IgE immunoglobulin.


You may be asked to give urine samples that can be tested in different ways:

  • Urinalysis: Multiple myeloma can cause organ damage. Urinalysis -- a common test that looks at a sample of your urine -- can check how well your kidneys are working and tell if you might have kidney damage.
  • Urine protein level: Compared with normal plasma cells, myeloma cells produce too many immunoglobulin proteins. This test measures how much protein is in your urine.
  • Urine protein electrophoresis (UPEP): For this test, you'll need to collect your urine over a 24-hour period and keep it cool until you bring it into your doctor. If the M protein and what's known as the Bence Jones protein are in your urine, they can be signs of multiple myeloma. Higher levels may mean it's likely the cancer has spread.


To understand what's going on with your bones, you may have imaging and bone marrow tests:

Imaging studies: Your doctor may want to get a good look at your bones, specifically, the bone structure and the number and size of tumors in your bones. Bone changes are often a sign of multiple myeloma.

These tests might include:

  • X-rays, known as a bone survey or skeletal survey
  • MRI (magnetic resonance imaging): Powerful magnets and radio waves are used to make detailed images.
  • CT scan (computerized tomography): Several X-rays taken from different angles are put together to show more information.
  • PET scan (positron emission tomography): Radiation is used to make 3-dimensional color images.

This is a common test used to diagnose multiple myeloma. Your doctor will remove a piece of bone marrow or take a sample of cells from your body and check it in a lab under a microscope for signs of cancer. These types of biopsies are most often used to help diagnose multiple myeloma:

  • Bone marrow biopsy: The doctor will numb the top of your rear hip bone and remove a splinter of bone marrow tissue. They’ll look at the size and shape of the cells, how they’re arranged, how many there are to determine if myeloma cells are present.
  • Bone marrow aspiration: The doctor will numb the top of your rear hipbone and use a needle to take a sample of liquid bone marrow. They may request other tests on the aspirated liquid, such as:
    • Immunohistochemistry: This test treats cells from the biopsy with a special protein so they’ll change color. This helps identify myeloma cells.
    • Flow cytometry: This test treats the bone marrow sample with proteins that stick only to certain cells. It helps determine if the cells are abnormal, myeloma, another type of cancer, or a non-cancerous disease.
    • Cytogenetic analysis (karyotyping): This test looks for changes to chromosomes in bone marrow cells and myeloma cells. Changes in your DNA can give doctors an idea of how aggressive your myeloma is.
    • Fluorescence in situ hybridization (FISH): Doctors use special dyes to attach to your chromosomes and spotlight changes too small for other tests to find.

MyPRS: The Myeloma Prognostic Risk Signature test measures 70 genes. A computer program calculates a risk score based on the results, and you'll find out if you're at high risk or low risk for early relapse. This is a newer test and isn't used often.

SKY92 Multiple Myeloma Profiler – This looks at 92 genes. Like MyPRS, it also is available and has been validated.