Flow cytometry is of limited utility in the early identification of “Double‐hit” B‐cell lymphomas

Abstract

Background: B-cell lymphomas with concurrent translocations of MYC and BCL2 or BCL6, also known as ''double-hit'' lymphomas (DHL), are rare malignancies characterized by aggressive clinical behavior and poor prognosis. Previous reports suggest that decreased CD20 and/or CD19 expression by flow cytometry is relatively common in DHL and may help to identify cases requiring additional cytogenetic analysis.Methods: We conducted a retrospective analysis of 26 cases of DHL, and compared their flow cytometric characteristics to cases of Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). Cases were analyzed by four-color flow cytometry, and bivariate dot-plots were reviewed for light scatter characteristics, CD19, CD20, CD45, and surface light chain.Results: Relatively few DHL cases showed dim expression of CD19 or CD20, and statistically significant differences were found only in the frequency of dim CD19 expression between DHL and BL or DLBCL. Although concomitant dim CD19 and CD20 expression was exclusive to DHL, it was present in only a minority of cases.Conclusions: We conclude that although a subset of DHL expresses aberrant levels of CD19 and/or CD20 by flow cytometry, these findings are of limited utility in identifying cases requiring cytogenetic analysis due to their low frequency. Until more sensitive pathologic parameters can be identified and validated, the decision to perform cytogenetic analysis should rest on a combination of clinical, morphologic, and immunophenotypic features suggestive of high-grade, aggressive disease. V C 2013 International Clinical Cytometry Society

The utility of multiparametric seven‐color flow cytometry in the detection of double hit lymphoma in ascitic fluid samples

“…DHL and triple-hit lymphomas could arise from follicular and DLBCL following the acquisition of MYC rearrangement in the molecular pathologic evolution of the disease (2). Seven-color flow cytometric immunophenotyping could be more accurate than four-color studies for DHL diagnosis (3). Controversy has arisen regarding the utility of flow cytometry for the diagnosis of DHL.…”

Long-Term Results in Recipients of Combined HLA-Mismatched Kidney and Bone Marrow Transplantation Without Maintenance Immunosuppression

“…Limiting dilution assay to quantify cytotoxic T-lymphocyte precursor frequencies and IL-2-producing T helper frequencies were performed as described (20). Lymphocyte subsets were monitored by flow cytometry as previously described (21). …”

Diagnosis of ‘double hit’ diffuse large B-cell lymphoma and B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma: when and how, FISH versus IHC

“…14,20,47 Flow cytometric demonstration of dim CD20 and/or dim CD19 to help identify DHL has also been reported, but others find it to be of limited utility because most cases do not have these features. [48][49][50] But what about the role of MYC IHC? It has been reported that finding Ն70% MYCϩ cells had a sensitivity of 100% and specificity of 93% for a MYC break.…”