What is Multiple Myeloma?

Multiple myeloma is a form of blood cancer that occurs in white blood cells called plasma cells. It can cause a number of problems throughout the body. The disease is actually called “multiple myeloma” because the cancerous cells can appear at multiple sites.

How does multiple myeloma develop?

Like other types of blood cells, plasma cells are made in the bone marrow. Multiple myeloma begins when a plasma cell acquires a genetic mutation that causes it to grow abnormally. It becomes a malignant myeloma cell.

The myeloma cell multiplies rapidly. Soon, myeloma cells begin to accumulate in the bone marrow. They prevent the marrow from making healthy red blood cells, white blood cells, and platelets. Eventually, the patient will start to feel unwell with a variety of symptoms.

What causes multiple myeloma?

Scientists don’t know what exactly triggers the genetic mutations that lead to multiple myeloma. This means that it’s impossible to predict who will get myeloma and who will not.

Certain groups of people are known to be more at risk for myeloma than others. If you have a number of risk factors and are concerned, talk with your doctor. There may be ways to lower your risk.

How does multiple myeloma impact the body?

Multiple myeloma can damage the body in several different ways. It can cause

  • Painful, brittle bones: When myeloma cells build up in the bone marrow, they form tumors. These tumors can lead to bone pain and even fractures.
  • Kidney disease: Myeloma cells are still technically plasma cells. Plasma cells make antibodies, which are proteins that help the immune system to function. Myeloma cells produce an antibody known as the “M protein.” However, unlike normal antibodies, the M protein doesn’t help the immune system. Instead, it builds up in the bloodstream. The high amounts of M protein in the blood make it difficult for the kidneys to filter it out, leading to kidney damage.
  • Increased infections: Because of the proliferating myeloma cells, the bone marrow is unable to produce adequate numbers of healthy white blood cells. This leaves the patient more susceptible to infections and disease.
  • Hypercalcemia: “Hypercalcemia” means that there is too much calcium in the blood. This occurs when multiple myeloma has broken down the bones to such an extent that calcium leaks into the bloodstream. Hypercalcemia can make patients feel sick.

Other plasma cell neoplasms

Besides multiple myeloma, there are other types of plasma cell neoplasms:

  • Monoclonal gammopathy of undetermined significance (MGUS) is generally not cancerous but can progress to multiple myeloma.
  • Smoldering myeloma is another inactive form or precursor of multiple myeloma. Patients with smoldering myeloma have an excessive number of plasma cells in the bone marrow without evidence of organ damage. Although smoldering myeloma has a greater risk of progressing to active multiple myeloma, some patients never do. Some patients with smoldering myeloma may be considered for treatment after a detailed discussion with their physician.
  • Amyloidosis is a rare but serious protein deposition disease caused by an abnormal protein called amyloid that builds up in tissues or organs. As the amount of amyloid protein deposits increase, they interfere with function and may cause organ failure. Systemic amyloidosis is the most common. Amyloidosis may be associated with certain blood cancers like multiple myeloma.
  • Plasmacytoma is a cancerous tumor caused by myeloma cells. It differs from multiple myeloma in that there is only a single tumor site. Sometimes it can be cured. Plasmacytomas can either be of the bone or extramedullary, in which the tumor is outside the bone, usually in tissues of the throat, tonsil or paranasal sinuses. They can progress to multiple myeloma.