Lymphoplasmacytic Lymphoma with Only Lambda Light Chain Monoclonal Paraprotein Expression.

Area of Science:

• Hematology
• Oncology
• Rare Diseases

Background:

• Lymphoplasmacytic lymphoma (LPL) is a rare B-cell neoplasm, typically associated with Waldenstrom macroglobulinemia (WM) and IgM paraprotein.
• Non-IgM LPL is exceptionally rare, accounting for a small subset of LPL cases, and presents unique diagnostic and therapeutic challenges.
• Lambda light chain production in non-IgM LPL is exceedingly uncommon, with limited reported cases.

Purpose of the Study:

• To report a case of non-IgM LPL with lambda light chain paraprotein production.
• To discuss the diagnostic and therapeutic challenges associated with this rare subtype of LPL.
• To highlight the potential significance of MYD88 L265P mutation testing in non-IgM LPL.

Main Methods:

• Case report of a 41-year-old female diagnosed with non-IgM LPL.
• Fluorescence in-situ hybridization (FISH) for MYD88 L265P mutation detection in bone marrow.
• Treatment with ibrutinib and rituximab.

Main Results:

• The patient presented with non-IgM LPL, lambda light chain paraprotein, and normal immunoglobulin levels.
• MYD88 L265P mutation was detected.
• The patient showed an initial response to ibrutinib and rituximab but ultimately died 8 months post-diagnosis.

Conclusions:

• Non-IgM LPL, particularly with lambda light chain production, is a rare and challenging hematological malignancy.
• MYD88 L265P mutation testing may be valuable for therapeutic considerations in non-IgM LPL.
• There is a critical need for the development of new and effective treatments for non-IgM LPL.