Diagnostic value of STMN1, LMO2, HGAL, AID expression and 1p36 chromosomal abnormalities in primary cutaneous B cell lymphomas

Abstract

Introduction

distinction between primary cutaneous follicular lymphoma (PCFL) and primary cutaneous marginal zone lymphoma (PCMZL) is challenging as clear-cut immunophenotypic and cytogenetic criteria to segregate both entities are lacking.

Materials and methods

to better characterize PCFL and PCMZL and to define criteria helpful for the differential diagnosis, we compared expression of immunohistochemical markers (LMO2, HGAL, STMN1, AID, MNDA) and the presence of cytogenetic abnormalities previously described in nodal follicular lymphoma (BCL2 and BCL6 breaks, 1p36 chromosomal region deletion (del 1p36)) in a series of 48 cutaneous follicular and marginal zone lymphomas (CFL and CMZL).

Resultats

immunostaining for STMN1, LMO2, HGAL and AID allowed the distinction between CFL and CMZL and STMN1 was the most sensitive marker (100% CFL, 0% CMZL). LMO2, HGAL and AID were positive in 93,2%, 82,1%, 86,2% CFL (all CMZL negative). MNDA was expressed in both entities without significant difference (10,3% CFL, 30,8% CMZL, p=0,18). BCL2, BCL6 breaks and the del 1p36 were present in 16,7%, 10,7% and 18,5% CFL and none CMZL. Finally 3 and 29 CFL were reclassified as secondary cutaneous follicular lymphomas (SCFL) and PCFL without significant differences concerning phenotypic and cytogenetic features. BCL2, BCL6 breaks and the del 1p36 were present in 11,1%, 8% and 16,7% PCFL and did not impact prognostic.

Conclusion

LMO2, HGAL, STMN1 and AID but not MNDA are discriminant for the recognition between CFL and CMZL. BCL2, BCL6 rearrangements and the del 1p36 have a role in the pathogenesis of PCFL, the latest being the commonest alteration.

This article is protected by copyright. All rights reserved.

http://ift.tt/2siFPDG