Chronic lymphoproliferation

B-cell disease; the existence of rare cases of T-CLL has been debated

Annual incidence 30/10⁶; represents 70% of lymphoid leukaemias, 1/4 of all leukaemias; median age: 60-80 yrs, 2M/1F

Diagnosis is often delayed, due to the lack of symptoms (therefore, median survival from the begining of the disease may be much more than median survival from diagnosis). The patient may present with enlarged lymph nodes, splenomegaly, lymphocytosis > 4 5 X 10⁹/l; hypogammaglobulinemia in 60%

Typically, proliferation of mature small lymphocytes of normal morphology; lymphocytes with more abundant cytoplasm may be present. When prolymphocytes are 10% or greater they are classified as chronic lymphocytic leukaemia-prolymphocytic leukaemia.

The main immunophenotypic features that define B-CLL are: the predominant population shares B-cell markers CD19, CD20, and CD23 with the CD5 antigen, in the absence of other pan-T-cell markers; the B-cell is monoclonal with regard to expression of either kappa or lambda; and surface immunoglobulin (slg) is of low density. Not only are these characteristics generally adequate for a precise diagnosis, but, importantly, they distinguish CLL from uncommon disorders such as PLL, hairy-cell leukemia, mantle-cell lymphoma, and other lymphomas. Further, the Matutes score based on the most common marker profile in CLL, CD5+, CD23+, FMC7- and weak expression (+/-) of surface immunoglobulin (SIg) and CD22, can distinguish between typical and atypical CLL by assigning scores that range from 5 (typical of CLL) to 0 (atypical for CLL).

Binet staging is used for therapeutic intervention. The treatments options are: watchful waiting for symptoms, radiation therapy, chemotherapy, surgery such as splenectomy. Those being tested in clinical trails are monoclonal antibodies, chemotherapy with stem cell transplant.

Evolution: unrelated causes and disease-related infections are the 2 major causes of death ; others: autoimmune hemolytic anaemia and thrombocytopenia; transformation into Richters disease or into prolymphocytic leukaemia (in 10%). Some patients with CLL survive for many years without therapy with minimal signs and symptoms, during the entire disease course and have a survival time similar to age-matched controls, whereas others have a rapidly deteriorating blood counts and organomegaly. Rai et al and Binet et al devised staging: less than 3 lymph nodes, HGB