LMP-1 expression in a case of AIDS-related PCNSL (DLCL). The microphotograph shows that the tumor is polymorphous and predominantly consists of large tumor cells displaying an immunoblastic-plasmacytoid morphology. LMP-1 positivity is evident as cytoplasmic staining in some large tumor cells. Paraffin-embedded tissue section, APAAP immunostaining, hematoxylin counterstain. Original magnification × 630.