Immunohistochemistry in Gastroenterohepatopancreatobiliary Epithelial Neoplasia

Immunohistochemistry (IHC) has broad applications in neoplastic gastrointestinal surgical pathology. Although classically used as a diagnostic tool, IHC increasingly provides prognostic and predictive information. This review highlights 11 key uses of IHC (Box 1). Emphasis is placed on specific clinical applications and qualitative aspects of interpretation. Common pitfalls are specifically highlighted. The potential application of emerging markers is discussed in relation to several of the 11 topics. In many instances, an immunostain serves as a surrogate for specific molecular genetic events. Survey of relevant articles forms the evidence basis for this review.