Chylothorax as an Initial Presentation of Waldenström Macroglobulinemia: Report of Two Cases.

BACKGROUND: Chylothorax is an uncommon form of pleural effusion defined by the pathological accumulation of chyle within the pleural space. Although thoracic duct injury constitutes the most frequent cause, nontraumatic causes, including malignancies and lymphoproliferative disorders, merit consideration. Waldenström macroglobulinemia (WM), a lymphoplasmacytic lymphoma (LPL) characterized by bone marrow involvement and an immunoglobulin M (IgM) monoclonal gammopathy, rarely presents with pulmonary complications, and its association with chylothorax has been described in only a limited number of reports. CASE PRESENTATION: We describe two patients who presented with right-sided chylothorax as the initial manifestation of WM. Both patients underwent comprehensive diagnostic evaluation confirming LPL and received multimodal management comprising therapeutic pleural interventions and WM-directed systemic therapy. CONCLUSION: Chylothorax is a rare manifestation of WM and may represent the initial presentation of the disease. Early recognition, comprehensive diagnostic evaluation, and initiation of appropriate disease-directed therapy are essential for symptom control and management. Further studies are needed to better characterize the mechanisms, optimal treatment strategies, and long-term outcomes of WM-associated chylothorax.