Waldenström macroglobulinemia presenting as bilateral bloody pleural effusion: A case report.

Rationale: Pleural effusion, especially bilateral bloody pleural effusion, is a rare complication of Waldenström macroglobulinemia (WM). Pleural effusion in patients with WM has many causes, such as infection, tumor invasion of the pleura, and rupture of the thoracic duct or its branches. Patients with WM presenting to the respiratory department with chest tightness and shortness of breath need more differential diagnosis by respiratory physicians, which is helpful for effective treatment.