Hairy cell leukemia patients treated with 2-chlorodeoxyadenosine or 2-deoxycoformicin achieve a very high number of therapeutic responses. After complete remission, i.e. minimal residual disease, we cannot demonstrate the disease activity, splenomegaly, or lymphadenopathy; moreover, there comes to normalization of hemoglobin concentration, leukocyte count, and platelet count. No leukemic cells in peripheral blood or bone marrow smears can be seen with the use of staining techniques. They can be demonstrated immunohistochemically in decalcified trephine bone marrow biopsies with the use of DBA.44 antibody together with their morphologic features. For quantification of leukemic cells we use LUCIA-M image analysis.

        Key words: hairy cell leukemia – immunohistochemistry – minimal residual disease – trephine bone marrow biopsy – DBA.44