[A case of MALT lymphoma simultaneously associated with gastric and pulmonary involvement].

A 52-year-old man had been treated by hemodialysis because of IgA nephropathy since 1994. Gastric MALT lymphoma was diagnosed in January 2007. Radiation therapy was performed for 4 weeks (40Gy) and the response was complete remission (CR) by September 2007. He was admitted to our hospital in February 2008 because of an abnormal chest shadow. Chest CT showed multiple cystic lesions with calcification and consolidation. Transbronchial lung biopsy from the area of consolidation (left S5) showed pulmonary invasion of small lymphoid cells. PCR analysis showed clonal rearrangement of the heavy chain of the immunoglobulin gene. Accordingly, MALT lymphoma was diagnosed. Rituximab infusion was performed, because CD20 immunostaining was positive and he had been treated by hemodialysis. The abnormal chest shadow was presented since gastric MALT lymphoma was diagnosed. We considered that MALT lymphoma occurred simultaneously in the stomach and lung.