In the early stages of multiple myeloma, patients have few or no symptoms of the condition, which may only be suspected or diagnosed by chance as a result of routine blood or urine testing. Diagnosis may also be suspected if certain symptoms are present.
Some of the tests involved in diagnosing multiple myeloma include:
- A detailed medical history and examination of clinical symptoms. Specific symptoms that are looked for include signs of anemia, bleeding, infection and bone pain.
- Routine blood tests are carried out to check hemoglobin levels, the red blood cell count and white blood cell count, which may all be decreased in multiple myeloma. The erythrocyte sedimentation rate may be raised due to the presence of abnormally high protein levels and blood calcium may also be raised. Blood tests also provide information about liver and kidney function.
- Myeloma cells produce large amounts of an abnormal protein that can affect the kidneys and a urine test can be used to measure the levels of protein in the urine as well as to indicate kidney function. The abnormal proteins are called monoclonal light chains or Bence Jones protein.
- Imaging studies include X-ray, CT (computed tomography) scan, MRI (magnetic resonance imaging) scan, PET (positron emission tomography) scan and bone scan. These scans are performed to look for evidence of the cancer within affected bones.
- Bone marrow biopsy – This is a test used to confirm a diagnosis of multiple myeloma. A special hollow needle is inserted into one of the bones (usually the pelvis) and a sample of the bone marrow is taken. The procedure is brief and carried out under local anesthetic. The sample is examined in the laboratory for the presence of cancerous plasma cells.
The international staging system (ISS) for diagnosing myeloma was outlined by the International Myeloma Working Group in 2005 and includes the following criteria:
- Stage I – A β2-microglobulin level of less than 3.5 mg/L, an albumin level equal to or more than 3.5 g/dL.
- Stage II
- A β2-microglobulin level less than 3.5 mg/L, albumin level less than 3.5 g/dL
- A β2-microglobulin equal to or more than 3.5 mg/L, an albumin level less than 5.5 g/dL
- Stage III – A β2-microglobulin level of 5.5 mg/L or more.