Causes and Diagnoses

Causes and Diagnoses of Multiple Myeloma

The exact cause of multiple myeloma in unknown, but scientists are beginning to understand how changes in DNA can make plasma cells become cancerous. Cancers can be caused by mutations in the DNA that turn on the genes that promote cell division or turn off the genes that suppress tumor growth.

Certain factors can increase your risk of developing multiple myeloma. Risk factors for multiple myeloma include:

  • Age: Less than one percent of cases are diagnosed in people younger than age 35
  • Gender: Men are slightly more likely to develop multiple myeloma
  • Race: African-Americans are more likely to have this cancer
  • Exposure to radiation: This accounts for a small number of cases
  • Family history: Having a sibling or parent who has it may increase your risk
  • Exposure to chemicals: Your risk may increase if you work with certain substances, such as petroleum products
  • Certain health conditions: Being overweight or obese may increase your risk
  • Certain plasma cell diseases: Disorders such as solitary plasmacytoma and monoclonal gammopathy of undetermined significance (MGUS) are considered "precursors" to myeloma and may or may not evolve into multiple myeloma

If you have any of the risk factors for multiple myeloma consult your physician with any concerns.


To diagnose multiple myeloma, your physician will assess your medical history and perform a physical exam. Additional diagnostic tests may be performed, including:

  • X-ray: An X-ray is a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. Bone scans are used to evaluate for bone involvement with most cancers, but they are unreliable in multiple myeloma
  • Blood and urine tests: These tests are used to look for proteins or other substances that are more likely to be seen in the blood or urine of people with myeloma
  • Bone marrow aspiration and/or biopsy: A procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size and maturity of blood cells and/or abnormal cells
  • Skeletal survey: This involves a series of plain X-rays of all of the major bones in the body
  • Magnetic resonance imaging (MRI): MRI is a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body
  • Computed tomography scan (CT scan): A CT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. CT scans are more detailed than general X-rays but often not quite as detailed as MRI scans
  • Positron emission tomography (PET) scan: A PET scan is a radioactive-tagged glucose (sugar) is injected into the bloodstream. Tissues that use the glucose more than normal tissues, such as tumors, can be detected by a scanning machine. PET scans can be used to find small tumors throughout the body

Once the diagnosis is made, additional testing may be needed to assess the stage of the cancer.