B-cell chronic lymphocytic leukemia (B-CLL) represents most common leukemia in Western Europe and North America adult population. Accurate diagnosis of the disease based on leukemic cell immunophenotype analysis has principal importance in differential diagnostic distinction of B-CLL from other leukemized B-cell malignancies. Determination of strong and independent prognostic parameters in early and intermediate disease stage patients could lead to consideration of appropriate therapeutic approach. Assessment of IgVH mutational status, ZAP70 and CD38 expression levels, genetic aberrations and p53 gene mutations constitute modern tools for understanding of biologic behavior and potential aggressiveness of leukemic clone.

        Key words: B-cell chronic lymphocytic leukemia, diagnosis, immunocytology, cytogenetic, IgVH mutations, prognosis