Premium
Nodal reactive and neoplastic proliferation of monocytoid and marginal zone B cells: an immunoarchitectural and molecular study highlighting the relevance of IRTA 1 and T‐bet as positive markers
Author(s) -
Bob Roshanak,
Falini Brunangelo,
Marafioti Teresa,
Paterson Jennifer C,
Pileri Stefano,
Stein Harald
Publication year - 2013
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12160
Subject(s) - marginal zone , immunohistochemistry , pathology , biology , nodal , immunoglobulin light chain , lymphoma , antibody , b cell , immunology , medicine , anatomy
Aims Marginal zone B cells ( MZC s) and monocytoid B cells ( MBC s) appear to be related lymphoid cells that take part in reactive and neoplastic marginal zone proliferations. These lesions are not yet well characterized, and the aim of this study was to find better diagnostic criteria for them. Methods and results We analysed 60 nodal lesions with MBC and/or MZC proliferation for their morphological, immunophenotypic, molecular genetic and IG gene rearrangement features. On the basis of the results of the rearrangement assay and immunoglobulin light chain restriction, the lesions were divided into reactive and neoplastic groups. Among the neoplastic lesions, polymorphic and monomorphic subgroups emerged. All reactive lesions had morphological features of the polymorphic subgroup. By immunohistochemistry, IRTA 1 and/or T‐bet expression was found in all reactive lesions and in 90% of neoplastic lesions. Conclusions IRTA 1 and T‐bet are positive markers for the identification of MZC / MBC proliferations, and thus for the diagnosis of nodal marginal zone lymphoma ( NMZL ). Polymorphic and monomorphic subgroups of NMZL could be distinguished. Most morphological and immunophenotypic patterns in reactive and neoplastic nodal expansions of MZC s and MBC s overlapped. Therefore, PCR clonality assay of the immunoglobulin heavy and light chain gene loci is the most reliable method for their differentiation.