Figure 2: Lymph node biopsy: (a) low power view of H&E-stained section of lymph node biopsy showing diffuse effacement of the normal lymph node architecture by a mixed infiltrate comprised of small lymphocytes, plasma cells, histiocytes, and scattered large cells with vesicular chromatin, irregular nuclear contours, and conspicuous nucleoli (10x magnification). Relatively frequent mitoses were also observed scattered throughout the specimen. (b) EBV in situ hybridization analysis for the detection of EBV-encoded RNA (EBER) reveals abundant positive cells with dark nuclear staining, consistent with EBV infection. Arrows point to large atypical EBV-positive cells (100x magnification).