The impact of diagnostic immunohistochemistry on patient outcomes

Diagnostic immunohistology (DIHC) is a discipline that has been used clinically for at least two decades, but, because of medicolegal encumbrances, it has not been a part of many formal outcomes analyses during that time. Potential applications of this technology with a direct bearing on response to treatment include the accurate identification of infectious organisms, distinction between morphologically-similar undifferentiated tumors, separation of benign and malignant neoplasms, and prognostication of malignancies. The first two of those four roles may indeed have a quantifiable impact on case outcomes, but the last two applications have only questionable value in this specific context. This is an area of medicine in which formal outcomes analysis is greatly needed to help determine future practice patterns.