Causes

It's not clear what causes Waldenstrom macroglobulinemia.

Doctors know that the disease begins with one abnormal white blood cell that develops errors (mutations) in its genetic code. The errors tell the cell to continue multiplying rapidly.

Because cancer cells don't mature and then die as normal cells do, they accumulate, eventually overwhelming production of healthy cells. In the bone marrow — the soft, blood-producing tissue that fills in the center of most of your bones — Waldenstrom macroglobulinemia cells crowd out healthy blood cells.

Waldenstrom macroglobulinemia cells continue trying to produce antibodies, as healthy white blood cells do, but instead they produce abnormal proteins that the body can't use. The protein immunoglobulin M (IgM) accumulates in the blood, impairs circulation and causes complications.