This 60 y/o man underwent splenectomy for an enlarged spleen. Specimen showed multiple coalescent fleshy tumor nodules. The results of immunophenotyping by flow cytometry results were as follows; POSITIVE: CD20, CD10 (weak), and lambda; NEGATIVE: CD3, CD5, CD23. The tumor cells were also positive for BCL2 and BCL6 and had a high Ki-67 labeling index. The image shows a mixed population of centroblasts and immunoblasts.