[Pulmonary Waldenström's macroglobulinemia--a case report].

Area of Science:

• Hematology
• Pulmonology
• Oncology

Background:

• Waldenström's macroglobulinemia (WMG) is a rare lymphoproliferative disorder characterized by the production of monoclonal IgM antibodies.
• Pulmonary involvement in WMG is uncommon, often presenting as diffuse infiltrates or nodules.
• This case focuses on a rare presentation of WMG primarily affecting the lungs.

Observation:

• A 47-year-old male presented with dyspnea and a progressively enlarging pulmonary nodule.
• Initial hematological tests and bone marrow biopsy were unremarkable, complicating early diagnosis.
• Elevated serum IgM levels and detection of IgM kappa M-protein on immunoelectrophoresis were key findings.

Findings:

• Chest X-ray revealed a significant right middle lobe mass.
• Histological examination of the lung biopsy confirmed diffuse lymphoplasmacytoid cell proliferation.
• Immunohistochemistry (PAP method) demonstrated monoclonal IgM kappa within the cytoplasm of these cells, confirming pulmonary WMG.

Implications:

• This case underscores the importance of considering WMG in patients with unexplained pulmonary masses and elevated IgM.
• Effective treatment with VEPA chemotherapy led to significant reduction in both the pulmonary lesion and serum IgM levels.
• Highlights the potential for pulmonary manifestation as the primary presentation of WMG, requiring a multidisciplinary diagnostic approach.