AJHE2503 - CME/CMLE - How I diagnose B-cell lymphoproliferative disorders with plasmacytic differentiation-How I diagnose B-cell lymphoproliferative disorders with plasmacytic differentiation

How I diagnose B-cell lymphoproliferative disorders with plasmacytic differentiation

Pdf Summary

The article "How I Diagnose B-cell Lymphoproliferative Disorders with Plasmacytic Differentiation" by Jonathan H. Young, MD, PhD, and Olga Pozdnyakova, MD, PhD, provides a comprehensive review of diagnostic challenges and methodologies for B-cell lymphomas with plasmacytic differentiation, focusing primarily on lymphoplasmacytic lymphoma (LPL) and marginal zone lymphoma (MZL). These conditions are notable for overlapping histological and immunophenotypic features, making differential diagnosis complex.<br /><br />Key points include the importance of integrating molecular testing with clinical, laboratory, and radiologic data to diagnose B-cell lymphoproliferative disorders. The paper emphasizes that while MYD88 L265P mutation is a key marker for LPL, it can also appear in other B-cell lymphomas, necessitating cautious interpretation. MZLs are discussed as a heterogeneous group with distinct clinical presentations depending on the form—nodal, splenic, or extranodal. The authors underline the importance of a clinicopathologic approach in differentiating between LPL and MZLs, using case studies to illustrate diagnostic reasoning. <br /><br />Two case presentations highlight the diagnostic process:<br />1. A 65-year-old man with suspected aggressive B-cell lymphoma was ultimately diagnosed with splenic MZL due to specific clinicopathologic features, despite the presence of an MYD88 L265P mutation.<br />2. A 58-year-old woman presented a challenging differential between LPL and other lymphoproliferative disorders; high IgM paraprotein levels and clinical features led to an LPL diagnosis.<br /><br />The authors conclude by discussing the importance of understanding the molecular pathology, genetics, and specific markers in these lymphomas to aid diagnosis and treatment planning. They recommend that cases with atypical presentations may be best addressed by providing a broad diagnosis with a detailed discussion of the differential diagnoses. The lack of specific funding and conflicts of interest is noted.

Keywords

B-cell lymphoproliferative disorders

plasmacytic differentiation

lymphoplasmacytic lymphoma

marginal zone lymphoma

MYD88 L265P mutation

molecular testing

clinicopathologic approach

differential diagnosis

case studies

diagnostic challenges