hemolytic anemia occurs in about 5-10% of CLL patients, which is when one's own immune system attacks its own red blood cells.

A more serious complication called Richter's transformation (RT) occurs in 2-10% of patients with CLL. This is a process in which the original CLL cells convert to a far more aggressive disease that has the biology and histopathology of diffuse large B cell lymphoma or less commonly Hodgkin's lymphoma.