Newer, more comprehensive treatment endpoints in the clinical management of patients with inflammatory bowel disease necessitate a robust, accurate, and reproducible approach during the histologic examination of disease activity in specimens from these patients. Pathologists are increasingly being asked to evaluate and report histologic parameters that will enable more specific and focused treatment decisions in the quest for more complete disease remission. This review will summarize the terminology used, available scoring systems, use context, and appropriate interpretation of findings during this endeavor. Limitations and future concerns in this evolving landscape will also be considered.
Barrett's esophagus confers an increased risk for esophageal adenocarcinoma. Accurate detection and risk stratification of patients with Barrett's esophagus presents certain challenges. Current paradigms rely on endoscopic examination and histologic diagnosis in forceps biopsies, but this approach is limited by sampling error and interobserver variability. A variety of ancillary studies have been developed to attempt to address these limitations. These techniques employ alternative sampling strategies and/or detection of molecular and protein-level alterations associated with neoplastic progression. This article provides an overview of ancillary studies, including p53 immunohistochemistry, TissueCypher (Tissue Systems Pathology Test-9 [TSP-9]), WATS-3D, and epigenetic assays, among others.
Graft-versus-host disease (GVHD) continues to be a major cause of morbidity after allogeneic stem cell transplantation. This article summarizes current approaches to grading and reporting gastrointestinal GVHD while outlining key histopathological features, diagnostic thresholds, and interpretive challenges. It emphasizes the need for clinicopathologic correlation and awareness of common mimickers, and the growing role of plasma biomarkers in risk stratification/assessment. Emerging tools in artificial intelligence-enabled digital pathology and standardized reporting practices aim to improve diagnostic accuracy, reproducibility, and clinical relevance in the management of GVHD in modern practice.
Neoadjuvant therapy is employed to downstage many locally advanced gastrointestinal and pancreatic cancers, reduce tumor burden, and improve survival. However, treatment also produces gross and histologic therapy-related changes, confounding pathologic assessment and causing challenges for pathologists. The accuracy of post-therapy pathologic staging and assessment relies on meticulous specimen examination and cognizance of therapy-induced gross and histologic changes. Tumor regression grading (TRG) provides additional prognostic information and is an invaluable adjunct to pathologic staging after neoadjuvant therapy. This review provides an overview of standardized gross and histologic assessment of rectal adenocarcinomas, upper gastrointestinal tract carcinomas and pancreatic adenocarcinomas.
The histopathologist is an integral part of the specialty team involved in the diagnosis of rare and problematic gastrointestinal tract infections. Frequently, routine hematoxylin and eosin morphology, supported by various histochemical and immunoperoxidase stains, enables the rapid diagnosis of such infections. The recent advent of molecular technologies has further augmented the histopathologist's armamentarium. The role of various methodologies that can be applied in the workup of these cases, including those in the immunocompromised individual, is discussed and interpretation in the context of relevant clinical and microbiologic investigation findings, is highlighted.
