What is Myeloma (Basic version)

So what exactly is this thing?

While Dr. PZ in his non-alarmist way referred to it obliquely as a "malignancy of the blood" it is, to use starker terminology, cancer of the blood plasma. I had asked Dr. PZ if it was as bad as Leukemia and he said it was not...but honestly I'm not so sure. I gather that it depends upon what kind of Leukemia one is talking about. Anyhow...

Plasma cells are cells in the blood that help the body produce antibodies in order to fight off illness. One's bone marrow instructs the body to manufacture these cells (as well as white and red blood cells). In a healthy person, about 4% of one's bone marrow is represented by plasma cells. In Myeloma, one plasma cell has a genetic abnormality and it (as is the case in all cancer) doesn't live the normal life of a cell, but refuses to die. It divides, as all cells do, but it makes clones of itself that also refuse to die. Over time, the plasma cells crowd out the other components of the bone marrow and a person is left with no white blood cells or healthy plasma cells to fight infection, and no red blood cells. Thus, anemia is a common sign of Myeloma.

Myeloma cells also send instructions for other types of cells to be created, and these cells attack and eat bone. Typically, bones all over the place are affected and multiple tumors show up, hence the name Multiple Myeloma. Over time, bones are eaten up and this puts calcium into the bloodstream, which if unchecked wreaks havoc on the kidneys. A person with Myeloma, therefore, ultimately succumbs to either an opportunistic infection which the body cannot fight off, or severe renal failure.

Lovely.