Immunohistochemical localization of adenosine deaminase in human benign extrathymic lymphoid tissues and b‐cell lymphomas

Abstract

Immunomorphologic methods were utilized to localize adenosine deaminase (ADA) in extrathymic benign lymphoid tissues and B‐cell lymphomas. In reactive lymph nodes, tonsils and appendix, germinal centers displayed strong ADA‐positive nuclear staining in small cleaved lymphocytes and weak nuclear and/or cytoplasmic staining in large lymphoid cells. A significant proportion of ADA‐positive lymphocytes in the germinal centers were B‐cells. The mantle zone of secondary follicles did not stain for ADA. The plasma cells in the medullary cords demonstrated mainly cytoplasmic staining. In the spleen, ADA‐positive lymphocytes were located in the periarteriolar sheath and paratrabecular white pulp. In lymphoma B‐cells, patterns of ADA staining were similar to those observed in normal B‐lymphocytes of similar morphology. This study demonstrated that human normal and lymphoma B‐lymphoid cells are heterogeneous with respect to ADA expression. This heterogeneity appears to be associated with differentiation and/or proliferation of B‐lymphocytes. Cancer 53:70‐78, 1984. Copyright © 1984 American Cancer Society