Review ArticlesFluorescent In Situ Hybridization in Surgical Pathology PracticeGupta, Ruta FRCPA*,†; Cooper, Wendy A. PhD, FRCPA*,†,‡; Selinger, Christina PhD*; Mahar, Annabelle FRCPA*; Anderson, Lyndal FRCPA*,‡; Buckland, Michael E. PhD, FRCPA*,†,§; O’Toole, Sandra A. PhD, FRCPA†,∥,¶Author Information *Department of Tissue Pathology and Diagnostic Oncology †Royal Prince Alfred Hospital, Sydney Medical School, University of Sydney ‡School of Medicine, Western Sydney University §Department of Neuropathology, Royal Prince Alfred Hospital, Sydney, Australia ∥Garvan Institute of Medical Research ¶Australian Clinical Labs, Sydney, Australia The authors have no funding or conflicts of interest to disclose. Reprints: Ruta Gupta, FRCPA, Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, University of Sydney, Bld 94, Camperdown 2050, Sydney, Australia (e-mail: [email protected]). All figures can be viewed online in color at www.anatomicpathology.com. Advances In Anatomic Pathology: July 2018 - Volume 25 - Issue 4 - p 223-237 doi: 10.1097/PAP.0000000000000194 Buy Metrics Abstract There have been rapid and significant advances in diagnostic and predictive molecular techniques in recent years with profound impact on patient care. In situ hybridization (ISH) studies have become well entrenched in surgical pathology practice and their role in the evaluation of HER2 in breast carcinoma and their diagnostic utility in soft tissue pathology are well known. Fluorescent ISH is being increasingly used in other sites such as the head and neck and the gynecologic tract. Like most tests in surgical pathology, ISH studies require good quality tissue, correlation with clinical and histopathologic findings, and adherence to guidelines for optimal assay performance and interpretation. Although ISH studies are largely performed in tertiary centers, the tissue is often processed by a variety of laboratories and the referring pathologists are required to discuss the need, relevance, and significance of these tests and the results with their clinical colleagues. Here we review the predictive and diagnostic utility of fluorescent ISH studies in a variety of organ systems, the preanalytical factors that may affect the results, and the pitfalls in the interpretation that all practicing surgical pathologists should be aware of. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.