Multiple Myeloma and Plasma Cell Disorders

Multiple myeloma and other plasma cell neoplasms (cancers) are diseases in which the body makes too many plasma cells.

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.

There are several types of plasma cell neoplasms:

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. Learn more >>

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. Learn more >>

Waldenstrom's 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. Learn more >>

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. Learn more >>

SMM

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. Learn more >>