Flow Cytometry in the Differential Diagnosis of CD10-Positive Nodal Lymphomas

Marc Sorigue, MD; Mireia Santos-Gomez, MD; Martina Comes, MD; Minerva Raya; Sara Vergara; Gustavo Tapia, MD, PhD; José-Tomas Navarro, MD, PhD; Cristian Morales-Indiano, MD; Jordi Junca, MD, PhD

Disclosures

Lab Med. 2020;51(4):385-393. 

In This Article

Abstract and Introduction

Abstract

Background: Differences between follicular lymphoma (FL) and diffuse large B-cell lymphoma/high-grade B-cell lymphoma (DLBCL/HGBL) by flow cytometry are underexplored.

Methods: We retrospectively assessed flow cytometry results from 191 consecutive lymph node biopsies diagnosed with FL or DLBCL/HGBL.

Results: The only parameters that differed between the 2 groups in the derivation cohort were forward scatter and side scatter (P < 10−6; area under the curve [AUC], 0.75–0.8) and %CD23 (P = .004; area under the receiver characteristic operating curve, 0.64). However, since light scatter characteristics did not distinguish between grade 3 FL and DLBCL/HGBL, we set out to develop a model with high sensitivity for the exclusion of the latter. Several models, including FS and %CD23, were tested, and 2 models showed a sensitivity of >0.90, with negative predictive values of ≥0.95, albeit with low specificity (0.45 to 0.57).

Conclusion: Two simple models enable the exclusion of DLBCL/HGBL with a high degree of confidence.

Introduction

Flow cytometry (FC) is a rapid and reproducible tool to characterize lymphoid populations reliably. Although the diagnosis of lymphoma should be based on the histological analysis of the specimen, FC has a relevant role in guiding the diagnostic process, making it quicker and cheaper and offering clinicians and patients an early clue into the final diagnosis.

CD10 is, alongside CD5, the antigen that guides the diagnostic process of B cell disorders.[1] In lymph nodes (LN), it most often (although not exclusively) suggests the presence of a germinal-center derived malignancy. However, there are only a few series examining the cytometric differences between the most common entities within this group, follicular lymphoma (FL) and diffuse large B-cell lymphoma/high-grade B-cell lymphoma (DLBCL/HGBL).[2,3] Importantly, a key diagnostic difference, the presence of LN follicles/follicular dendritic cells, is not straightforwardly assessed by FC. This suggests that FC may have a limited role to play in this differential diagnosis.

The purpose of this study was to interrogate a cohort of patients with a diagnosis of germinal center-derived malignancies for cytometric differences between FL and DLBCL/HGBL.

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