Multiple myeloma

Definition

Multiple myeloma is a cancer of the plasma cells in bone marrow.

Causes, incidence, and risk factors

Multiple myeloma is characterized by the excessive growth and malfunction of plasma cells in the bone marrow. The growth of these extra plasma cells interferes with the production of red blood cells, white blood cells, and platelets. This causes anemia, susceptibility to infection, and increased tendencies toward bleeding.

As the cancer cells grow and expand in the bone marrow, they also cause pain and destruction of the bones. If the bones in the spine are affected, compression of the nerves may result causing numbness or paralysis.

Renal failure (kidney failure) is a frequent complication caused by excess calcium in the blood that results from bone destruction. Multiple myeloma mainly affects older adults. Other risk factors are unknown. This disease is rare and only 3 new cases per 100,000 people per year occur in the US.

Symptoms

• Bone or back pain
• Unexplained fractures
• Bleeding problems
• Increased susceptibility to infection
• Symptoms of anemia (such as tiredness, shortness of breath, and fatigue)

Signs and tests

• A bone marrow biopsy is performed.
• Serum protein electrophoresis is abnormal.
• Bone x-rays show fractures, hollowed out bone lesions.
• Chemistry profile shows increased serum calcium, total protein, and abnormal kidney function.
• Complete blood count (CBC) reveals low hematocrit (anemia), low red blood cell count (RBC), low platelets, and low white blood cell count (WBC).

• Bone lesion biopsy
• T-lymphocyte count
• Serum globulin electrophoresis
• Quantitative immunoglobulins (nephelometry)
• Serum immunoelectrophoresis
• ESR
• Febrile-cold agglutinins
• Cryoglobulins
• Blood differential
• Ionized calcium
• Protein in urine
• Urine immunofixation
• Urine immunoelectrophoresis
• Calcium in urine
• Bence-Jones protein (quantitative)
• 24-hr urine protein

Treatment

The goal of treatment is to relieve symptoms, since chemotherapy and even transplant rarely lead to permanent cure. Complete remission is unusual.

People who have mild disease -- or for whom the diagnosis is in doubt -- are usually observed without treatment. Some people have a slow-developing form which takes years before it causes symptoms. When the disease advances or causes symptoms, treatment is begun.

Chemotherapy and localized radiation therapy for relief of bone pain or treating a bone tumor may be useful. Bone marrow transplantation in younger patients has been shown to increase disease-free and overall survival, but it has significant risks.

Several promising new treatments including thalidomide, proteosome inhibitors, and arsenic trioxide are currently being investigated in clinical trials. Discuss participation with your doctor.

Symptoms of high serum calcium levels are treated, and dehydration is avoided to help maintain proper kidney function.

Support Groups

The stress of illness may be eased by joining a support group whose members share common experiences and problems. See cancer - support group.

Expectations (prognosis)

The average (median) survival of people with multiple myeloma is about 3 years, but this depends on the patient's age and the stage of disease. Some cases are very aggressive, while others take years to progress -- so discuss your individual condition with your doctor.

Complications

• Renal failure
• Increased susceptibility to infection (especially pneumonia)
• Paralysis from tumor or spinal cord compression
• Bone fractures

Calling your health care provider

Call your health care provider if you experience decreased urine output.

Call your provider if you have multiple myeloma and infection develops, or numbness, loss of movement, or loss of sensation develops.

Illustrations

Cryoglobulinemia - of the fingers

Immune system structures

Antibodies

Page Content:

Plasma cell dyscrasia; Plasma cell myeloma; Malignant plasmacytoma; Plasmacytoma of bone ; plasma cell dyscrasia; cell myeloma plasma