Localization and phenotype of EBV-positive cells in IM tonsil sections. (A) EBER-specific in situ hybridization with 35S-labeled RNA probes reveals numerous extrafollicular EBV-positive cells (black granular labeling). A small number of EBV-positive cells are also present within the GC. (B) Double labeling reveals that a proportion of extrafollicular EBV-positive cells (black) coexpress CD38 (red). Sections were examined under a Nikon Eclipse 80i microscope (Nikon GmbH, Dusseldorf, Germany) using either a Nikon Plan Apochromat 10×/0.45 objective lens (panel A) or a Nikon Plan Apochromat 40×/0.95 objective lens (panel B). Digital images were obtained with a Nikon Digital DS-5M camera and acquired using Digital Sight DS-5M-L1 image acquisition software.
