MARK R. WICK, M.D.
It is right and proper that each time a new technology enters clinical usage, the procedure must be validated adequately by comparison with existing methods, using appropriately- and stringently- characterized biological substrates. Indeed, several international Pathology societies have devoted much time and effort over the years to outlining and testing processes for that purpose. Guidelines and proficiency programs now exist—provided by the College of American Pathologists (CAP) and other regulatory bodies—for the quality-assurance of immunohistochemistry, in-situ nucleic acid hybridization, polymerase chain reaction-based assays, and other techniques used in the clinical laboratory (1).
In light of that reality, it has become increasingly apparent over time that the most basic of all tools in anatomic pathology—histochemical staining of tissue samples with hematoxylin & eosin (H&E)—is only passingly considered in the same context. CAP inspectors are indeed required to make a subjective evaluation of each laboratory’s H&E preparations (1), but, sadly, no objective standards really exist for judging their adequacy. All too often, a minimalistic approach is applied; in other words, if the sections can be interpreted at all microscopically, they are felt to be acceptable.
I believe that this is an important contributing factor to the playing-down of morphological skill, in the current practice of anatomical pathology. If H&E sections are suboptimal, one feels uncomfortable in basing a definite diagnostic conclusion on them. The result is either hyper-equivocation in reporting, or an immediate turning to non-or quasi- morphological methods as alternatives to microscopy (2). Needless to say, the second of those actions delays case-disposition, and it increases the cost of anatomic pathology services in the healthcare system at-large.
How can this situation be changed? There is certainly no easy remedy for the problems cited above, but, at the very least, anatomic pathologists must exercise the directorial roles that they have in the histology laboratory. Even histotechnologists without formal certification can be taught to perform good H&E stains, using the many help-sites on the internet and a variety of printed materials on that topic (3-7). Laboratory physician-directors must then review the daily output of slides with careful attention to quality, stressing the particulars of good microtomy, tissue-mounting, and the proper differentiation of stains. Even though health systems have become more and more insular with time, the trading of representative H&E-stained slides between different laboratories is another positive step down the road to improved quality. Pathologists on the receiving end of such exchanges can then critique the senders’ work-products, making constructive criticisms whenever they can. Formal documentation of that activity is recommended as well.
With improved H&E “substrates” to work with, it will no doubt be surprising to some practitioners that they will develop progressively-increasing levels of skill and confidence in morphological interpretation. Changes in national healthcare are on our doorsteps, with increasing emphasis on cost-effectiveness. Well-trained pathologists with good skills in microscopy can provide a huge diagnostic bargain to the system (8). However, that will only occur if greater consistency is attained in the universal production of high-quality H&E sections.
2. Shah AA, Frierson HF Jr, Cathro HP: Analysis of immunohistochemical stainusage in different pathology practice settings. Am J Clin Pathol 2012; 138: 831-836.
7. Carson F, Hladik C: Histotechnology: A Self-Instructional Text (3rd Ed), ASCP Press, Chicago, 2009.8. http://en.wikipedia.org/wiki/Anatomical_pathology