Immunohistochemical algorithms and gene expression profiling in primary cutaneous B-cell lymphoma

Pasquale Cretella,Anna Lucia Peluso,Caterina Picariello,Immacolata Cozzolino,Massimo Triggiani,Alessandro Puzziello,Valentina Giudice,Francesco Sabbatino,Antonio Ieni,Pio Zeppa,Alessandro Caputo

doi:10.1016/j.prp.2022.153804

Abstract

Objectiveto assess whether immunohistochemical (IHC) algorithms used to classify the cell of origin (COO) of nodal Diffuse Large B-cell lymphoma (nDLBCL) in Germinal Center type (GCB) and non-GCB subtypes may be applied to Primary Cutaneous B-cell lymphoma (PCBCL) too, and which of these algorithms performs better on PCBCL. DesignRetrospective case control study. SettingPathology Department of the University Hospital “San Giovanni di Dio e Ruggi d′Aragona” Salerno, Italy. ParticipantsFourteen PCBCL, including Primary Cutaneous follicle centre lymphoma (PCFCL) and primary cutaneous diffuse large B-cell lymphoma, Leg type (PCDLBCL-LT) and 14 nDLBCL were evaluated for 7-year period (January 2011 to December 2017). Primary cutaneous marginal zone cell lymphoma (PCMZL) cases were not included in the present study. InterventionEvaluation of immunohistochemical CD10, BCL6, MUM1/IRF4, BCL2, MYC and Ki-67 expression and classification according to three different algorithms. Gene expression profiling (GEP) was performed on the same series using Lymph2Cx assay (Nanostring). The data obtained were compared and analysed. ResultsAll the IHC algorithms showed 13 GCB and 15 non-GCB. GEP showed 12 GCB, 12 activated B cell–type and 4 unclassified. ConclusionsThe PCBCL were classifiable as GCB and non-GCB like the nDLBCL as IHC algorithms were concordant to GEP and produced the same results.

Highlights

IntroductionPrimary cutaneous B-cell lymphoma (PCBCL) is a heterogeneous group of lymphoproliferative disorders, which accounts for 20–25% of all primary cutaneous lymphomas [1]
What is already known on this topic: Primary cutaneous lymphomas (PCBCL) are classified in Primary cutaneous marginal zone cell lymphoma (PCMZL), Primary Cutaneous follicle centre lymphoma (PCFCL) and PCDLBCL-LT
What this study adds: Data obtained in our series support the reliability of both Gene expression profiling (GEP) and IHC algorithms in the prognostic and predictive evaluation of Primary Cutaneous B-cell lymphoma (PCBCL) with accuracy comparable to that reported for nDLCBL

Summary

Introduction

Primary cutaneous B-cell lymphoma (PCBCL) is a heterogeneous group of lymphoproliferative disorders, which accounts for 20–25% of all primary cutaneous lymphomas [1]. The discrimination between PCDLBCL-LT and other PCBCL, PCFCL with diffuse growth pattern and predominance of centroblasts is often investigated [5] For this purpose, the application of immunohistochemistry (IHC) algorithms used to subclassify nDLBCL in GCB and non-GCB might be useful but has not been validated on PCBCL. The aim of the present study is to assess whether the IHC algorithms utilized to classify the cell of origin (COO) of the nDLBCL may be applied on PCBCL, and which of these algorithms performs better on PCBCL For this purpose, a series of diffuse PCFCL and PCDLBCL-LT has been investigated by IHC and their phenotypes have been compared to an additional series of corresponding nDLBCL. The data obtained have been classified using different algorithms and validated by GEP, which is the gold standard for this classification

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