The Pathology of Reactive Lymphadenopathies: A Discussion of Common Reactive Patterns and Their Malignant Mimics

Abstract

Context.—Distinguishing between a reactive and a neoplastic lymphoid proliferation is a clinically significant task frequently performed by the surgical pathologist in routine practice. Objectives.—To highlight common situations in lymph node pathology where reactive changes and lymphoma may be misdiagnosed. Data Sources.—Data sources are peer-reviewed journal articles, textbooks, and clinical experience. Conclusions.—This review aims to refresh and enhance the surgical pathologist's awareness of the shared and distinguishing features of select reactive and neoplastic lymphoproliferations, which in turn will allow the surgical pathologist to make more accurate diagnoses and avoid the pitfalls of misdiagnosis. This will be done by describing a selection of commonly encountered reactive histologic changes observed in lymph nodes, present the lymphomas with which they share overlapping features, outline the features that distinguish them, and describe an approach to making an accurate diagnosis and avoiding a misdiagnosis in each scenario.