Downregulation of CD10 in leukaemic phase of follicular lymphoma: A silent deception

Abstract

Follicular lymphomas (FL) are frequent B-cell-derived malignancies, generally demonstrating an indolent evolution. Peripheral blood and bone marrow involvement by FL cells is infrequent. The aim of this study was to evaluate morphological features including immunophenotypic analysis of leukaemic follicular lymphoma on flow cytometry. The present study included 13 cases diagnosed on flow cytometry as follicular lymphoma involving peripheral blood or bone marrow over a period of 2 years (May 2010 to May 2012). Clinical presentation, complete blood count, peripheral smear, bone marrow aspirate and biopsy, lymph node biopsy and immunophenotypic profile by flow cytometric analysis of cases were reviewed. We observed in 13 patients a leukaemic phase of FL at the onset of the disease. Twelve of them had concomitant lymph node involvement whereas one patient had pure follicular cell leukaemia. In seven of 13 cases, there was absence of CD10 on flow cytometric analysis of circulating cells. Out of these seven cases, a lymph node biopsy was done in six cases, and all six cases showed CD10-positive neoplastic germinal centres. © 2013 Springer-Verlag Berlin Heidelberg.