An unusual reoccurrence of Waldenstrom's macroglobulinemia as pleural effusions that had a discordant response with treatment.

A 77-year-old female with a past medical history of Waldenstrom's macroglobulinemia presented with progressive shortness of breath and a newly diagnosed left pleural effusion. Numerous diagnostic studies were performed on the patient and finally a pleural biopsy confirmed pulmonary involvement of Waldenstrom's macroglobulinemia. As past studies have shown, Waldenstrom's involvement as a pulmonary process is uncommon. Unexpectedly, treatment with rituximab and fludarabine did decrease the patient's serum immunoglobulin M levels, but her pleural effusions never improved.