[Case of pulmonary MALT lymphoma with follow-up imaging for 10 years].

Although abnormal shadow in the left upper lung of an 84-year-old male patient was confirmed in an examination in November 1996, follow-up observation was discontinued. In July 2006, he first visited our department with a chief complaint of shortness of breath, and was hospitalized because of an abnormal shadow in the left upper lung field and left pleural effusion. Since atypical lymphocytes were found in the pleural effusion, and positive cellular surface markers CD19 and 20, and chromosomal aberration of t (11 ; 18) (q22 ; q21) were confirmed, extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) was diagnosed. Transbronchial lung biopsy of the left upper lobe confirmed small lymphocyte-like cellular infiltration, as seen in the pleural effusion, and CD20 immunostaining was positive, leading to the diagnosis of MALT lymphoma. In addition, serum immunoelectrophoresis demonstrated the development of macroglobulinemia as a complication. This case is valuable as changes diagnostic image over 10 years can be compared.