# MYD88‐mutated Lymphoplasmacytic Lymphoma With Monoclonal Immunoglobulin G: A Case Report

## TL;DR

A rare case of lymphoplasmacytic lymphoma secreting IgG instead of IgM is reported, highlighting the importance of considering this diagnosis even without typical IgM markers.

## Contribution

This case report expands the understanding of lymphoplasmacytic lymphoma by presenting an atypical IgG-secreting variant.

## Key findings

- The patient had LPL secreting monoclonal IgG instead of the usual IgM.
- The patient was treated with bortezomib, dexamethasone, and rituximab due to disease progression.
- This case emphasizes the need to consider LPL in differential diagnosis even without IgM.

## Abstract

Lymphoplasmacytic lymphomas (LPL) are usually associated with serum monoclonal immunoglobulin M (IgM). Nevertheless, in some cases, these cells may secrete IgA or IgG monoclonal proteins or remain non‐secretory. We report a case from a patient with LPL‐secreting IgG who developed anaemia and splenomegaly during the disease course that necessitated treatment with bortezomib, dexamethasone, and rituximab. The case illustrates the need for clinicians and pathologists to consider LPLs as a differential diagnosis also without a serum monoclonal IgM.

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