Factors determining whether diffuse large B-cell lymphoma samples are detected by flow cytometry

Area of Science:

• Hematology
• Immunophenotyping
• Oncology

Background:

• Flow cytometry (FCM) is a standard diagnostic tool for mature B-cell neoplasms (MBN).
• Diffuse large B-cell lymphoma (DLBCL), a prevalent MBN, is sometimes misdiagnosed or missed by FCM.
• Understanding factors contributing to FCM detection failure in DLBCL is crucial for improving diagnostic accuracy.

Purpose of the Study:

• To investigate factors associated with the failure of flow cytometry (FCM) to detect diffuse large B-cell lymphoma (DLBCL).
• To identify specific sample characteristics and protein expression levels that correlate with missed DLBCL diagnoses by FCM.

Main Methods:

• Retrospective analysis of 135 DLBCL cases diagnosed using eight-colour FCM.
• Comparison of clinical, FCM, histopathological, and genetic data between DLBCL cases detected and not detected by FCM.
• Statistical analysis to identify significant differences and correlations.

Main Results:

• 16% (22 out of 135) of DLBCL cases were not detected by FCM.
• Samples with a lower percentage of total events as lymphocytes and a higher percentage of T cells among lymphocytes were less likely to be detected.
• High MYC protein expression on immunohistochemistry was associated with a lower likelihood of DLBCL being missed by FCM.

Conclusions:

• Several factors influence the rate at which DLBCL is missed by FCM, even with advanced eight-colour analysis.
• The study highlights the limitations of FCM in detecting all DLBCL cases, emphasizing the need for complementary diagnostic methods.
• Diagnostic yield of FCM for DLBCL can be affected by sample composition and specific protein expression profiles.