​Our body produce various kind of white blood cell as part of the immune system and one of them is called lymphocytes. Chronic lymphocytic leukaemia (CLL) is a disease of lymphocytes, where there is a high lymphocyte cell count in the circulating blood and associated enlarged lymph nodes. There is a similar condition called small lymphocytic lymphoma (SLL) which shares the same disease characteristic but present with enlarged lymph node without high lymphocytes cell count in the blood.