Special ArticlePractical Approaches on CD30 Detection and Reporting in Lymphoma DiagnosisXu, Mina L. MD*; Gabali, Ali MD, PhD†; Hsi, Eric D. MD‡; Fedoriw, Yuri MD§; Vij, Kiran MD∥; Salama, Mohamed E. MD¶; Ramchandren, Radhakrishnan MD#; O’Malley, Dennis MD**; Wick, Mark R. MD††; Battistella, Maxime MD, PhD‡‡; Gru, Alejandro A. MD††Author Information *Department of Pathology & Laboratory Medicine, Yale University School of Medicine, New Haven, CT †Wayne State University School of Medicine, Detroit, MI ‡Department of Laboratory Medicine, Cleveland Clinic, Cleveland, OH §Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC ∥Department of Medicine/Oncology, Washington University School of Medicine, St Louis, MO ¶Department of Pathology, University of Utah, Salt Lake City, UT #Department of Medicine, Division of Hematology/Oncology, University of Tennesse, Knoxville, TN **Neogenomics Laboratories, Fort Myers, FL ††Departments of Pathology and Dermatology, University of Virginia, Charlottesville, VA ‡‡Pathology Department, Université de Paris, Hôpital Saint-Louis, Paris, France Conflicts of Interest and Source of Funding: A.A.G. is a consultant and investigator for Seattle Genetics, Stemline Therapeutics, and Innate Pharma. The remaining authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Alejandro A. Gru, MD, School of Medicine, University of Virginia, Emily Couric Clinical Cancer Center, Charlottesville, VA (e-mail: [email protected]). The American Journal of Surgical Pathology: February 2020 - Volume 44 - Issue 2 - p e1-e14 doi: 10.1097/PAS.0000000000001368 Buy Metrics Abstract While our understanding of the biology of CD30 in lymphoma continues to evolve, our need to detect and measure its expression at the protein level remains critically important for diagnosis and patient care. In addition to its diagnostic and prognostic utility, CD30 has emerged as a vehicle for drug targeting through the antibody-drug conjugate brentuximab-vedotin (BV). Given the numerous ways that CD30 is utilized and its emergence as a predictive/prognostic biomarker, pathologists must come to a general consensus on the best reporting structure and methodology to ensure appropriate patient care. In this manuscript, we review the indications for testing, various modalities for testing, technical challenges, pitfalls, and potential standards of reporting. The following questions will try to be addressed in the current review article: What defines a “POSITIVE” level of CD30 expression?; How do we evaluate and report CD30 expression?; What are the caveats in the evaluation of CD30 expression? Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.