In a small number of people with CLL, the leukaemia can suddenly change and start to grow much more quickly. This is called transformation. It can change into another type of leukaemia (prolymphocytic leukemia) or a type of lymphoma (cancer of the lymphatic system) called Richter’s syndrome.
Transformation may be found when you have a blood test - it shows a high number of leukaemia cells.
Sometimes the first sign of transformation may be an increase in symptoms. Symptoms can include a high temperature (fever), weight loss, and a sudden swelling of affected lymph nodes, especially in your abdomen. However, symptoms such as a high temperature and weight loss can occur for many other reasons. It is important to remember that transformation does not happen for most people with CLL.