Impacts of New Concepts and Technologies on the Practice of Diagnostic Pathology: An Emory University Perspective

Abstract

The only constant in pathology is change. New diseases are discovered; new pathogens emerge; diagnostic criteria, expert opinions, and favorite systems of terminology remain forever in flux. Arcane concepts, techniques, and instruments that were once confined to the research laboratory continually find their way into our daily clinical practice. No sooner have we mastered clusters of differentiation, intracellular signaling cascades, driver mutations, and DNA repair pathways than we must pivot to confront cancer immunotherapy, next-generation sequencing, mass spectrometry in the microbiology laboratory, and torrents upon torrents of terabytes. Far more than other specialists, pathologists also have to stay attuned to the ever-changing methods, ideas, needs, and expectations of our many clinician partners, who turn to us for expert advice and rely on us always to stay abreast of their own diverse fields. Through it all, pathologists learn and adapt. The dynamism of our specialty is key to its mission, its challenges, and its joy.This Special Section of the Archives celebrates change. Focusing on a handful of subspecialties in one large, university-based pathology department, we invited teams of faculty to highlight some of the major trends that are affecting their own current practices, and how they are adapting their clinical workflows to accommodate. In a profession as fluid as pathology, some waves of change that first come ashore in an academic, quaternary-care health center are destined before long to wash over pathology practices everywhere. So the authors have tried throughout to emphasize trends that already are, or seem likely soon to become, relevant to pathologists in a wide range of practice types and settings. The 10 resulting essays (5 making up Part I that begins after this introduction, and the remainder in Part II that continues in the April issue) provide snapshots of just how deeply various new methodologies and concepts have penetrated each subspecialty, in some cases with transformative effects.Technology looms large. Not surprisingly, gene-sequencing methods are finding application across the full range of subspecialties represented here, with implications for diagnosis, treatment, and prognostication. For some, this is just the latest in a long string of innovations: In the opening essay of Part I, for example, Fasano and colleagues trace the history of how once-novel serologic assays and mixed-lymphocyte reactions in the histocompatibility laboratory have gradually given way to sequence- and informatics-based approaches to tissue typing, so that “virtual cross-matches” are now a routine first step in bone marrow and solid-organ transplant. Hematopathology is likewise famous as an early adopter of new analytic technologies, and for reinventing its diagnostic schemes accordingly, so it is no surprise to read in the review by S. Li and coauthors that cytogenetic, sequencing, and gene-array methods are now inextricably part of the workup of hematologic disorders, and are yielding revolutionary insights.But who would have anticipated that neuropathology, too, would now rely so heavily on cytogenetic and mutational information, with genomic data poised to supersede histopathology in the workup, for example, of low-grade gliomas, as reported by Neill et al? Or that next-generation sequencing would be proving useful in the diagnostic evaluation of pancreatic cyst fluid and bile-duct brushings, as Reid et al report? Or that genotyping now offers a more efficient way to identify red cell donors for sickle cell or thalassemic patients who have been highly sensitized by multiple prior transfusions, as Fasano et al describe? For diagnosing salivary tumors, Griffith and colleagues see little impact thus far of gene arrays and targeted therapies, but they find that testing for distinctive chromosomal translocations (using fluorescence in situ hybridization) can be a powerful adjunct to immunostaining, particularly for