Chronic lymphocytic leukemia (CLL) is a B-cell neoplasm defined by the presence of at least 5×109 G/L monoclonal B lymphocytes in the peripheral blood. It is the most common type of leukemia in adult patients from Western countries. CLL is characterized by a gradual accumulation of small, longliving, immunologically dysfunctional, morphologically mature-appearing B-lymphocytes in blood, bone marrow and lymphoid tissues. It has also been reported that CLL cells have a proliferation rate higher than previously recognized, particularly in the lymphoid tissues. The flow cytometry analysis of typical CLL identifies a monotypic B-cell population expressing a low level of surface immunoglobulins, light chain being either kappa or lambda-, CD5+, CD19+, CD23+, CD79b (dim), negative for FMC7 and CD10. Clinical presentation, course and outcome are highly variable. Interphase fluorescent in situ hybridization (I-FISH) identifies chromosomal abnormalities in about 80% of cases, most commonly involving 13q14 (55%), 11q22-23 (18%), or 17p13 deletions (7%) and trisomy 12 (16%). Therefore, five prognostic categories have been defined with a statistical model, showing the shortest median survival and treatment-free intervals in patients harboring 17p and 11q deletions, followed by trisomy 12 and a normal karyotype, whereas 13q deletion as the sole abnormality is associated with the best prognosis. We report here a rare case of CLL in a 54 year-old-man.
Keywords: BCL2; CLL; t(14 ;18); trisomie 12.