Immunohistochemical example of aGCB subtype of DLBCL that is positive for the germinal center markers CD10 and bcl-6 and co-expresses MUM-1. (A) A rare case of pediatric DLBCL with a non-GCB immunophenotype with negative staining for CD10 and bcl-6 and positivity for MUM-1 (B). Images were captured with a Zeiss Axioskop 40 microscope (Carl Zeiss, Jena, Germany) equipped with a 40×/0.75 objective lens and an RT slider camera (Diagnostic Instruments, Sterling Heights, MI). Images were processed with MetaVue software (Diagnostic Instruments) and Adobe Photoshop (Adobe Systems, San Jose, CA).