Abstract
Purpose: :
It is important to distinguish orbital mucosa-associated lymphoid tissue (MALT) lymphoma and benign lymphoproliferative disorders such as IgG4-related lymphoproliferative disease (IgG4) and reactive lymphoid hyperplasia (RLH), since work-up as well as therapeutic strategy can vary greatly. In this study, we evaluate the immunophenotypic profiles of patients with orbital lymphoproliferative disorders as an aid in distinguishing orbital MALT lymphoma from benign disorders such as IgG4 or RLH.
Methods: :
Biopsies proven 32 consecutive patients with newly diagnosed as orbital MALT lymphoma (n=17), RLH (n=10), and IgG4 (n=5) at Tokyo Medical University Hospital from 2006 to 2011 were recruited in this study. All cases of orbital MALT lymphoma patients showed Ig gene rearrangement. For flow cytometry analysis, cells were stained using fluorochrome-conjugated antibodies against mAb to CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD16, CD19, CD20, CD23, CD25, CD30, CD34, CD56 and polyclonal antibodies directed against Κ and .
Results: :
Expression of CD25 was higher in patients with orbital MALT lymphoma compared to IgG4 or RLH (p<0.001). CD23 which is a low-affinity Fc receptor for IgE, is significantly expressed in orbital IgG4 or RLH compared to MALT lymphoma (p<0.001). T cell surface antigens such as CD2, CD3, CD4 were significantly expressed in orbital IgG4 or RLH compared to MALT lymphoma (p<0.001). Of MALT lymphoma, 9 cases showed Κ light-chain and 8 Κ light-chain reconstruction.
Conclusions: :
These results suggest that the applicability of CD23 and CD25 analysis by flow cytometry as useful markers in distinguishing orbital MALT lymphoma from benign lymphoproliferative disorders such as IgG4 or RLH.
Keywords: tumors • flow cytometry • cytokines/chemokines