Patterns of Immunohistochemistry Utilization in Metastases to the Liver

摘要

Immunohistochemistry (IHC) is a well-established adjunct to histomorphology enabling pathologists to make more accurate diagnoses helping their patients and clinical colleagues in their decision-making. Over the past 3 decades, we have been witnessing a steady increase in IHC utilization by pathologists not only because of the introduction of new antibodies but also due to our deeper understanding of its role in tailoring treatment options. In the current era of personalized medicine, we use IHC on a regular basis for genetic and therapeutic determinations, well beyond its traditional use in diagnosis.1'2 Consequently, our paradigm of antibody evaluation and our overall approach to IHC has significantly changed.3 As a complement to this phenomenon, efforts have been made by several research groups and professional organizations to study practice patterns and suggest guidelines for IHC utilization.4 This is to acknowledge that the increased dependency on IHC in our daily pathology practice comes with its own cost both in terms of its technical and professional interpretive aspects. Additional cost, albeit less amenable to quantitation, is the mental effort spent by the pathologists when the IHC results are nonconclusive or contradictory. To date, although some aspects of pathology practice are privileged by having established IHC best practice guidelines,5'6 IHC utilization is left for the most part to the discretion of the individual pathologist and their own interpretation of the literature available in their respective areas. As a result, we see high variability of the same IHC panel utilization even within the same institution.7'8