# Case Report: Pulmonary and gastrointestinal involvement in a rare case of Waldenström’s Macroglobulinemia in French Guiana

## TL;DR

A rare case of Waldenström’s Macroglobulinemia in a 60-year-old man showed unusual lung and gut involvement, highlighting the need for detailed biopsies during exams.

## Contribution

This case report emphasizes the importance of systematic biopsies in detecting extramedullary manifestations of Waldenström’s Macroglobulinemia.

## Key findings

- Lymphoplasmacytic infiltration was found in bronchial and gastrointestinal mucosa despite normal endoscopic appearance.
- The case underscores the need for biopsies even when no visible lesions are present during endoscopy.
- Extramedullary manifestations in Waldenström’s Macroglobulinemia may be underdiagnosed without thorough histological evaluation.

## Abstract

Waldenström’s Macroglobulinemia (WM) is a rare lymphoproliferative disorder characterized by the proliferation of lymphoplasmacytic cells producing monoclonal immunoglobulin M (IgM). Extra-hematopoietic involvement, although rare, can affect the gastrointestinal tract in approximately 4% of cases and the lungs in 3–5% of cases. This case highlights the diversity of extramedullary manifestations in WM and underscores the importance of performing pulmonary and gastrointestinal endoscopies with systematic biopsies for optimal disease management.

We report the case of a 60-year-old Haitian man diagnosed with WM in January 2023 following an episode of acute respiratory failure. Biopsies revealed lymphoplasmacytic infiltration in both the bronchial and gastrointestinal mucosa. Biopsies revealed lymphoplasmacytic infiltration in both the bronchial and gastrointestinal mucosa, despite normal macroscopic findings during gastrointestinal endoscopy.

This case emphasizes the importance of systematic biopsies during endoscopic examinations, even in the absence of visible lesions, to detect lymphoplasmacytic infiltration in WM. These findings could help in changing the approach to disease management and improving patient outcomes.