Abstract: One senior patient diagnosed as  Waldenstrom's  macroglobulinemia(WM) for  more than four years was discussed in detail. The patient had immune pancytopenia during the course of disease and was treated with hormone for a long time. After the treatment with ibrutinib for one month,  capillary leak syndrome (CLS) appeared. The manifestations were  high fever,  dyspnea,  edema of the whole body and hypotension. Laboratory and imaging examination showed pulmonary infection,  large amount of effusion in bilateral thorax,  hypoalbuminemia,  hyponatremia,  and atrial fibrillation. In critical condition,  the patient was treated with colloidal solution and hormone to inhibit inflammatory reaction and reduce capillary permeability. After the treatment with  vasoactive drugs and other aggressive measures,  the condition still had no improvement. The case was used to explore the causes of CLS and related clinical significance.

Key words: Waldenstrom macroglobulinemia, ibrutinib, capillary leakage syndrome