IMMUNOPHENOTYPICAL FEATURES OF BLASTOID VARIANT OF MANTLE CELL LYMPHOMA

Abstract

Blastoid variant (BV) constitutes about 30% of all histopathological subtypes of mantle cell lymphoma (MCL). It is very difficult to diagnose blastoid variant of mantle cell lymphoma (MCL-BV) on the basis of cytomorphology alone. MCL-BV with leukemic presentation mimics lymphoblastic lymphoma, centroblastic large cell lymphoma, acute lymphoblastic leukemia and some types of acute myeloid leukemia. Objective: to define cytomorphological and immunophenotypical criteria for diagnosing MCL-BV in the setting of the appearance of pathological cells in peripheral blood and the development of the infiltration foci in bone marrow. Object and methods: immynophenotyping and flow cyto­metry of neoplastic cell in 55 patients with classic mantle cell lymphoma and in 9 cases of MCL-BV with leukemic presentation were studied. Results: peripheral blood smears in most cases leukocytosis (60–130•10⁹/l) along with 50–90% abnormal blast or blast-line cells. On bone marrow examination the high level of cells also were seen. The abnormal blood and bone marrow cells of four patients with MCL-BV were: CD19⁺CD20⁺CD5⁺CD10^–CD23^–Cyclin D1⁺. Five patients have aberrant phenotype of blast-line cells in the form of anomal expression CD5, CD10, CD19 antigenes. Cyclin D1 expression confirmed the diagnosis of MCL-BV in all patients. Conclusion: the results of cytomorphological, enzymocytochemical studies and immunophenotyping using the panel of specially selected MABs allow identification of the blood and bone marrow substrate cells in the MCL-BV in the stage of leukemia, and conduct differential dia­gnosis with other forms of non-Hodgkin’s lymphomas and acute leukemias of lymphoid and myeloid origin.