Utility of flow cytometric analysis of mast cells in the diagnosis and classification of adult mastocytosis

The diagnosis of bone marrow (BM) involvement in mastocytosis has mainly be en based on conventional histology. Nevertheless, in recent years, three ma jor methodological advances have been made: the measurement of serum trypta se levels, the immunohistochemical assessment of mast cell (MC) tryptase, a nd the immunophenotypical characterization of BMMC using flow cytometry (FC M). The most characteristic immunophenotypic feature in mastocytosis is the coexpression of CD2 and CD25 antigens, which are never present in normal B MMC and constitute a phenotypic hallmark of BMMC in adult mastocytosis. Suc h observations would support the need to include the immunophenotypic analy sis of MC in the diagnosis of mastocytosis. (C) 2001 Elsevier Science Ltd. All rights reserved.