MIB1 and diffuse large B-cell lymphoma: Biopsy and pathology analysis revealed a diffuse large B-cell lymphoma (DLBCL), with positive staining for CD20, CD79a, BCL2 and BLC6, but negative for CD10; 30% of the cells were positive for MIB-1 but MUM1 (IRF4) staining was negative, suggesting a germinal center-type lymphoma.