If multiple myeloma is suspected or the risk factors are present, there are tests to determine the status of a patient vis-à-vis the disease.

Multiple myeloma may be suspected in cases of unexplained incidence of a high erythrocyte sedimentation rate (ESR) and anemia.

Urine tests
Urine is tested to determine the level of M proteins (monoclonal proteins or myeloma proteins), a substance that can be extensively produced by myeloma plasma cells. This protein, if found in the urine, is called Bence Jones protein. Quantitative metrics of the Bence Jones protein is required to establish a myeloma diagnosis, and further monitor the progress of the disease.

Blood tests
Blood is tested for blood cell counts, uric acid levels, calcium levels, the percentage of plasma cells in the bone marrow, and for kidney function. Blood tests also reveal the presence of another abnormal protein that is produced by the myeloma cells – beta-2-microglobulin. High calcium levels, due to the breakdown of bone tissue and the release of calcium into the blood causes an impaired kidney function. This raises serum creatinine levels.

A recent recommendation for multiple myeloma diagnosis, an immunoassay called serum free light chain assay, is being used if the disease is suspect but the abnormal protein levels are low. This test may determine whether the disease has progressed beyond the MGUS (monoclonal gammopathy of undetermined significance) to multiple myeloma.

Imaging tests
Imaging tests for suspected multiple myeloma cases include a skeletal survey. A skeletal survey scans for “lytic lesions,” a condition where bone tissue disappears due to myeloma activity. An x-ray of the skull looks out for “punched-out lesions” or “pepper-pot skull.” MRI scans are more sensitive than simple X-rays to detect lytic lesions. A condition named soft-tissue plasmacytomas refers to bone lesions. Sometimes CT scans are used to measure the size of these lesions. Bone scans, a different type of imaging technique are not generally used in multiple myeloma cases, as they do not add value to a patient’s workup.

Bone marrow examination
A sample of bone marrow is drawn using a long needle (bone marrow aspiration and biopsy), and tested for the existence of multiple myeloma cells. This test is known as a bone marrow biopsy and is used to determine the extent to which the abnormal plasma cells have occupied the bone marrow. There are special tests such as fluorescence in situ hybridization (FISH) to analyze and study genetic abnormalities. This test also determines the types of abnormalities in the cells, and how quickly they are multiplying.

The diagnosis of multiple myeloma assigns a stage and a risk category based on the test findings. The disease can be classified from Stage I to Stage III, where Stages I and II, indicate the aggressiveness of the myeloma, and Stage III indicates that the disease has affected the bones, kidneys and other organs. The risk category helps the physician to determine the treatment options and the prognosis.

Since multiple myeloma is diagnosed by a series of tests, the International Myeloma Working Group (IMWG) has set out certain criteria to confirm a diagnosis of symptomatic multiple myeloma. They are

• A certain minimum percent of myeloma (clonal) plasma cells on a bone marrow biopsy
• Presence of monoclonal protein (M protein) in either urine or blood
• A positive four-component test called CRAB for
  • Higher than normal Calcium levels (hypercalcemia)
  • Kidney or Renal insufficiency
  • Anemia
  • Bone lesions (lytic lesions or osteoporosis)

All the tests should return a positive to return a diagnosis of multiple myeloma.