A physician who suspects that a patient may have multiple myeloma will first take the patient’s medical history and perform a physical examination. To diagnose and determine the extent of the disease, a variety of tests may be ordered, including:

• Electrophoresis. Serum protein electrophoresis (SPEP) is a procedure used to examine the blood for the presence of abnormal antibody known as monoclonal immunoglobulin. Urine may also be examined for this protein with a urine protein electrophoresis (UPEP). These tests may be used to diagnose multiple myeloma because finding the abnormal immunoglobulin in the blood and/or urine can indicate the presence of a plasma cell tumor.
  
  
• Beta-2-microglobulin test. High levels of the protein beta-2-microglobulin in the blood may also indicate myeloma, although it is also elevated in other diseases, such as lymphoma.  
  
  
• A complete blood count (CBC) may also be ordered. A CBC is a blood test that measures the number of red blood cells, white blood cells and platelets in a sample of blood, as well as the amount of hemoglobin in the red blood cells and additional factors.
  
  
• Blood chemistry tests. These tests measure the level of calcium and other chemicals in the blood. They are used to monitor changes in liver or kidney function caused by myeloma or treatment with certain chemotherapy drugs.
  
  
• 24-hour urine test. This test measures the amount of certain substances in urine collected for 24 hours. An abnormally high amount of protein may indicate multiple myeloma.
  
  
• Bone marrow biopsy and aspiration. Usually performed at the same time, these procedures may be ordered to confirm a diagnosis of multiple myeloma. A bone marrow aspiration involves using a thin needle to collect a small sample of liquid bone marrow. A bone marrow biopsy uses a larger needle to remove a piece of bone marrow. 
  
  
• Bone x-rays. This test uses low doses of radiation to produce images of bone on film or fluorescent screens. It can reveal signs of bone destruction caused by the cancer cells and the hormones they release.
  
  
• CAT scan (computed axial tomography). This test allows for multiple x-rays to be taken from different angles around the patient. In multiple myeloma patients, CAT scans (also called CT scans) can detect bone damaged caused by the disease. CAT scans may also be used to guide a biopsy needle into a suspected area. This procedure is known as a CAT-guided needle biopsy.

• MRI (magnetic resonance imaging). This test uses a powerful magnetic field to create images of structures and organs within the body allowing a computer to produce clear cross-sectional or three-dimensional images. It may be ordered to determine if the disease has caused bone destruction. As with CAT scans, a contrast material may be injected in the patient to improve the quality of the images.
  
  
• Cytogenetics. This test may be ordered to determine if the cells have too many chromosomes, or if the chromosomes have any translocations (the transfer of DNA from one chromosome to another), deletions (the loss of part of a chromosome), inversions (the rearrangement of DNA in part of a chromosome) or additions (all or part of a chromosome is duplicated and too many copies are found in a cell).
  
  
• PET scan (positron emission tomography). In this procedure, the patient receives an injection of glucose (sugar) containing a small amount of radioactive material. Once in the body, the radioactive glucose is absorbed by the cancer cells. A camera then scans the patient and detects where the radioactive glucose was absorbed. Areas of cancer cells appear as hot spots on the images. This test is typically used to determine if and where cancer has spread in the body.
  
  
• Bone density test. This procedure uses a special type of x-ray to measure bone loss.

Multiple myeloma cannot be diagnosed with any one test, according to the ACS. Instead, a physician will consider a number of factors including symptoms, findings from the physical examination, and results of blood, bone marrow, urine and imaging tests. To be diagnosed with the disease a patient must have the appropriate symptoms and at least one major criterion or at least three minor criteria.

Major criteria for the diagnosis of multiple myeloma:

• A biopsy reveals a plasma cell tumor.
  
  
• More than 30 percent of cells in the sample of bone marrow are plasma cells.
  
  
• The monoclonal immunoglobulin in the blood or urine is above a certain amount.

Minor criteria for the diagnosis of multiple myeloma include:

• Between 10 and 30 percent of cells in the bone marrow sample are plasma cells.
  
  
• Imaging tests have detected holes in bones (osteolytic lesions) due to tumor growth.
  
  
• There is insufficient normal antibody in the blood.
  
  
• Monoclonal immunoglobulin is detected, but not enough to fulfill a major criterion.