Original ArticlesPD-1, a Follicular T-cell Marker Useful for Recognizing Nodular Lymphocyte-predominant Hodgkin LymphomaNam-Cha, Syong H. MD* †; Roncador, Giovanna PhD‡; Sanchez-Verde, Lydia PhD§; Montes-Moreno, Santiago MD*; Acevedo, Agustín MD∥; Domínguez-Franjo, Purificación MD¶; Piris, Miguel A. MD*Author Information *Lymphoma Group, Molecular Pathology Programme ‡Monoclonal Antibodies Unit, Biotechnology Programme §Histology and Immunohistochemistry Unit, Spanish National Cancer Centre (CNIO) ∥Department of Pathology, Hospital Universitario de la Princesa ¶Department of Pathology, Fundación Hospital de Alcorcón, Madrid †Department of Pathology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain Supported by grants from the Ministerio de Sanidad y Consumo (G03/179, PI051623, PI052800), the Ministerio de Ciencia y Tecnología (SAF2005-00221, SAF2004-04286), and Fundación La Caixa, Spain. Correspondence: Syong H. Nam-Cha, MD, Molecular Pathology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), C/Melchor Fernández Almagro 3, E-28029 Madrid, Spain (e-mail: [email protected]). The American Journal of Surgical Pathology: August 2008 - Volume 32 - Issue 8 - p 1252-1257 doi: 10.1097/PAS.0b013e318165b0d6 Buy Metrics Abstract The nodularity and presence of T-cell rosettes surrounding the neoplastic cells has been described as a defining feature of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). We have explored the potential diagnostic value of a new marker (NAT105) that recognizes the antigen PD-1 in a series of 152 cases diagnosed as nodular sclerosis Hodgkin lymphoma, mixed cellularity Hodgkin lymphoma, lymphocyte-rich classic Hodgkin lymphoma, NLPHL, and T-cell/histiocyte-rich B-cell lymphoma (T/HRBCL). All the cases were immunostained with a panel of antibodies against CD10, bcl-6, CXCL13, CD57, and PD-1 (NAT-105). The series includes a set of cases diagnosed as NLPHL with diffuse areas, and a group of borderline cases with features between those of NLPHL and T/HRBCL. Results show that PD-1 (NAT-105) is an excellent immunomarker not only of follicular T-cell rosettes in NLPHL, but also of a subset of lymphocyte-rich classic Hodgkin lymphomas. However, it is not a unique and defining feature of NLPHL. The presence of PD-1–positive (NAT-105) T-cell rosettes seems to be an additional useful feature in the differential diagnosis of NLPHL and T/HRBCL, which is normally a controversial and difficult task. The standard T/HRBCL cases lack follicular T-cell rosettes, whereas most of the borderline cases between the 2 entities have follicular T-cell rosettes, thus suggesting a closer relation with NLPHL. © 2008 Lippincott Williams & Wilkins, Inc.