Multiple Myeloma and Other Plasma Cell Neoplasms

Multiple Myeloma and Other Plasma Cell Neoplasms at a Glance

• Multiple myeloma and other plasma cell neoplasms are diseases in which the body makes too many plasma cells.
• It is also called Kahler disease, myelomatosis, and plasma cell myeloma.
• It is treatable, but rarely curable.
• Since the advent of chemotherapy, survival has increased significantly.

What Is Multiple Myeloma?
Multiple myeloma is a systemic malignancy of plasma cells that is highly treatable but rarely curable. It is potentially curable when it presents as a solitary plasmacytoma of bone or as an extramedullary plasmacytoma. The median survival in the prechemotherapy era was about 7 months. After the introduction of chemotherapy, prognosis improved significantly with a median survival of 24 months to 30 months and a 10-year survival of 3%.

Estimated new cases and deaths from multiple myeloma in the United States in 2010 are 20,180 and 10,650 respectively.

Plasma cells develop from B lymphocytes (B cells), a type of white blood cell that is made in the bone marrow. Normally, when bacteria or viruses enter the body, some of the B cells will change into plasma cells. The plasma cells make a different antibody to fight each type of bacteria or virus that enters the body, to stop infection and disease.

Plasma cell neoplasms are diseases in which there are too many plasma cells, or myeloma cells, that are unable to do their usual work in the bone marrow. When this happens there is less room for healthy red blood cells, white blood cells, and platelets. This condition may cause anemia or easy bleeding, or make it easier to get an infection. The abnormal plasma cells often form tumors in bones or soft tissues of the body. The plasma cells also make an antibody protein, called M protein that is not needed by the body and does not help fight infection. These antibody proteins build up in the bone marrow and can cause the blood to thicken or can damage the kidneys. Plasma cell neoplasms can be benign (not cancer) or malignant (cancer).

There are different types of plasma cell neoplasms and not all of them are cancer. The following types of plasma cell neoplasms are cancer:

• Multiple myeloma.
• Plasmacytoma.
• Macroglobulinemia.

Monoclonal gammopathy of undetermined significance (MGUS) is not cancer but can become cancer.

Types of Plasma Cell Neoplasms

There are several types of plasma cell neoplasms. Plasma cell neoplasms include the following:

Multiple Myeloma

In multiple myeloma, abnormal plasma cells (myeloma cells) build up in the bone marrow, forming tumors in many bones of the body. These tumors may prevent the bone marrow from making enough healthy blood cells. Normally, the bone marrow produces stem cells (immature cells) that develop into three types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body.
• White blood cells that fight infection and disease.
• Platelets that help prevent bleeding by causing blood clots to form.

As the number of myeloma cells increases, fewer red blood cells, white blood cells, and platelets are made. The myeloma cells also damage and weaken the hard parts of the bones. Sometimes multiple myeloma does not cause any symptoms. The following symptoms may be caused by multiple myeloma or other conditions. A doctor should be consulted if any of the following problems occur:

• Bone pain, often in the back or ribs.
• Bones that break easily.
• Fever for no known reason or frequent infections.
• Easy bruising or bleeding.
• Trouble breathing.
• Weakness of the arms or legs.
• Feeling very tired.

A tumor can damage the bone and cause hypercalcemia (a condition in which there is too much calcium in the blood). This can affect many organs in the body, including the kidneys, nerves, heart, muscles, and digestive tract, and cause serious health problems.

Hypercalcemia may cause the following symptoms:

• Loss of appetite.
• Nausea or vomiting.
• Feeling thirsty.
• Frequent urination.
• Constipation.
• Feeling very tired.
• Muscle weakness.
• Restlessness.
• Mental confusion or trouble thinking.

Plasmacytoma

In this type of plasma cell neoplasm, the abnormal plasma cells (myeloma cells) collect in one location and form a single tumor, called a plasmacytoma. A plasmacytoma may form in bone marrow or may be extramedullary (in soft tissues outside of the bone marrow). Plasmacytoma of the bone often becomes multiple myeloma. Extramedullary plasmacytomas commonly form in tissues of the throat and sinuses; these usually can be cured.

Symptoms depend on where the tumor is.

• In bone, the plasmacytoma may cause pain or broken bones.
• In soft tissue, the tumor may press on nearby areas, causing pain or other problems. A plasmacytoma in the throat, for example, can make it difficult to swallow.

Macroglobulinemia

In macroglobulinemia, abnormal plasma cells build up in the bone marrow, lymph nodes, and spleen. They make too much M protein, which causes the blood to become thick. The lymph nodes, liver, and spleen may become swollen. The thickened blood may cause problems with blood flow in small blood vessels.

Symptoms of macroglobulinemia depend on the part of the body affected. Most patients with macroglobulinemia have no symptoms. A doctor should be consulted if any of the following problems occur:

• Feeling very tired.
• Headache.
• Nosebleeds.
• Vision changes such as blurred vision or bulging eyes.
• Dizziness.
• Pain, tingling, or numbness in the hands, feet, fingers, toes, or other parts of the body.
• Trouble walking.
• Confusion.
• Pain or a feeling of fullness below the ribs on the left side.
• Painless lumps in the neck, underarm, stomach, or groin.

Monoclonal Gammopathy of Undetermined Significance (MGUS)

In this type of plasma cell neoplasm, there are abnormal plasma cells in the bone marrow but there is no cancer. The abnormal plasma cells produce M protein that may be found during a routine blood or urine test. In most patients, the amount of M protein stays the same and there are no symptoms or problems. In some patients, MGUS may later become a more serious condition or cancer, such as multiple myeloma or lymphoma.

Multiple myeloma and other plasma cell neoplasms may cause a condition called amyloidosis.

In rare cases, multiple myeloma can cause organs to fail. This may be caused by a condition called amyloidosis. Antibody proteins build up and may bind together and collect in organs, such as the kidney and heart. This can cause the organs to become stiff and unable to work the way they should.

Risk Factors

Anything that increases your risk of getting a disease is called a risk factor. For multiple myeloma and plasmacytoma, other risk factors include the following:

• Being black.
• Being male.
• Having a brother or sister who has multiple myeloma.
• Being exposed to atomic bomb radiation.