VILLOUS LYMPHOCYTES IN BLOOD AND BONE MARROW IN SOME FORMS OF B-CELL LYMPHOID MALIGNANCIES

Abstract

The cytological and immunocytochemical features of the lymphocytes with villous morphology in peripheral blood and bone marrow in some B-lymphoproliferative disorders were studied. The diagnosis of hairy cell leukemia, a hairy cell leukemia variant, splenic marginal zone lymphoma and splenic diffuse red pulp small B-cell lymphoma was ascertained in accordance with the new revision of the WHO classification (2016). The neoplastic cells of hairy cell leukemia were determined by the presence of high tartrate resistant acid phosphatase (TRAP) activity. Cell surface expression of CD19, CD20 and CD21 antigens was detected. Also, the expression of CD25, CD103 and CD200, and in some cases cyclin D1, was found out. CD5, CD10 and CD23 were not detected. The immunophenotype of cells in splenic marginal zone lymphoma with villous processes also corresponded to the mature B cells. The expression of CD19, CD20 and CD21 was observed in all cases, CD11c – in 50% of patients, CD25 or CD5 – in 10% of patients. In 80% of patients, the pathologic cells did not show TRAP activity. In the bone marrow and peripheral blood cells of patients with diffuse red pulp lymphoma, TRAP activity was not detected. An immunophenotype in the hairy cell leukemia variant was different from those of classic HCL (CD19+CD20+CD22+CD103+CD11c+CD5–CD10–CD23–). Characterized immunophenotypical markers, which have differential diagnostic values in several forms of lymphoid tumors of B cell origin, will be important for the choice of treatment methods and prognosis