This smear shows a case of lymphoplasmacytic lymphoma (LPL) with bone marrow involvement and a monoclonal protein of the IgM type (Waldenström macroglobulinemia). The M-protein of this patient was as high as 45 g/L which causes increased viscosity of the blood and consequently reduced blood flow to organs. This led to respiratory and vision problems in this patient. It also causes rouleaux formation in the smear. Two monoclonal populations can be observed in this preparation.