T-cell/histiocyte rich large B-cell lymphoma. T-cell/histiocyte rich large B-cell lymphoma. (A) There are scattered large neoplastic cells, some of which resemble Reed–Sternberg cells, in a background of small lymphocytes and occasional histiocytes. (B) The CD20 immunohistochemical stain highlights the scattered large neoplastic B-cells and only rare small B-cells. Sonam Prakash, and Steven H Swerdlow J Clin Pathol 2007;60:1076-1085 Copyright © by the BMJ Publishing Group Ltd & Association of Clinical Pathologists. All rights reserved.