Physicians rely on a number of blood, urine, bone marrow, and imaging tests to diagnose multiple myeloma. These tests help determine if a patient has the disease, the stage and extent of disease throughout the body, and how active it is.
Blood and urine tests show whether excessive protein is in the blood, urine, or both — and determine the type of protein present. Blood tests also measure the number of normal red and white blood cells and platelets, and reveal the level of kidney function and several other factors that indicate the extent of disease.
Bone marrow aspiration and biopsy reveal the percentage of plasma cells in bone marrow. In a healthy person with normal bone marrow, plasma cells account for2 to 3 percent of the cells. Bone marrow containing more than 10 percent plasma cells is suggestive of multiple myeloma. Physicians also perform chromosome tests on bone marrow. Myeloma patients whose plasma cells contain chromosomal abnormalities usually have poorer outcomes than those with normal chromosomes.
X-rays, magnetic resonance imaging (MRI), and positron emission tomography (PET) are used to determine the number, size, and location of bone and soft tissue sites of disease.
Test results help physicians discover if myeloma is present and indicate whether the disease is stable and slow-growing, in which case it may not need to be treated. Tests also reveal if the disease is active and needs to be treated immediately.