Multiple Myeloma

Multiple myeloma is a type of cancer. Cancer is a group of many related diseases. Myeloma is a cancer that starts in plasma cells, a type of white blood cell. It's the most common type of plasma cell cancer.

Normal blood cells

Most blood cells develop from cells in the bone marrow called stem cells. Bone marrow is the soft material in the center of most bones.

Stem cells mature into different types of blood cells. Each type has a special job:

• White blood cells help fight infection. There are several types of white blood cells.
• Red blood cells carry oxygen to tissues throughout the body.
• Platelets help form blood clots that control bleeding.

Plasma cells are white blood cells that make antibodies. Antibodies are part of the immune system. They work with other parts of the immune system to help protect the body from germs and other harmful substances. Each type of plasma cell makes a different antibody.

Myeloma cells

Myeloma, like other cancers, begins in cells. In cancer, new cells form when the body doesn't need them, and old or damaged cells don't die when they should. These extra cells can form a mass of tissue called a growth or tumor.

Myeloma begins when a plasma cell becomes abnormal. The abnormal cell divides to make copies of itself. The new cells divide again and again, making more and more abnormal cells. These abnormal plasma cells are called myeloma cells.

In time, myeloma cells collect in the bone marrow. They may damage the solid part of the bone. When myeloma cells collect in several of your bones, the disease is called "multiple myeloma." This disease may also harm other tissues and organs, such as the kidneys.

Myeloma cells make antibodies called M proteins and other proteins. These proteins can collect in the blood, urine, and organs.

Source: MedicineNet.com
http://www.medicinenet.com/multiple_myeloma/article.htm