ARL Tumor characterization. (A) Distribution of tumor type is shown. Cases included DLBCL of the GCB (n = 21) and non-GCB (n = 14) subtypes, Burkitt lymphoma (n = 8), plasmablastic lymphoma (n = 5), B-cell lymphoma, unclassifiable (BCL, U; n = 7), and polymorphic lymphoproliferative disease (LPD; n = 1). EBV positivity shown was determined by EBER in situ hybridization. (B) LMP-1 expression as determined by immunohistochemistry. Fifty cases lacked LMP-1 in all tumor cells (left). Two cases showed LMP-1 expression in < 10% of tumor cells (middle). A tumor cell expressing LMP-1 is indicated by a black arrow, and representative tumor cells lacking LMP-1 are indicated by red arrows. Four cases expressed LMP-1 in > 90% of tumor cells (right). Original magnification ×600 with 60×/0.80 objective lens. Microscope: Olympus BX 41; camera: Olympus Q-COLOR3; software: QCapture, Version 2.9.8.0 (Quantitative Imaging Corporation).