Emerging Immunohistochemical Biomarkers for Myeloid Neoplasms

Pathologists can greatly improve patient care and advance the understanding of disease progression by adeptly employing relevant biomarkers when diagnosing myeloid neoplasms. Although the molecular era has ushered in countless molecular biomarkers in this field, the necessary techniques can be expensive and time-consuming. Novel immunohistochemical biomarkers can help to quickly and inexpensively render the correct diagnosis and predict response to targeted therapies. Hence, it is critical to continue studying and using new and promising immunohistochemical tools for myeloid neoplasms in our current era. To review the emerging biomarkers in myeloid neoplasms that can be identified by immunohistochemistry and to discuss their utility, staining patterns, and pitfalls. We conducted a scientific literature search of articles related to either a novel immunohistochemical marker or a new utility of an already known marker to assess myeloid neoplasms in PubMed from 2016 to September 30, 2021. We curated relevant contributing studies from the references and subsequent citations of the original articles. Immunohistochemistry is a powerful tool in analyzing biomarkers that play a significant role in the management of patients with myeloid neoplasms. We reviewed 5 immunohistochemical markers, namely, IDH1R132H, ERG, IRF8, GATA1, and NPM1. These markers, depending on the clinical scenario, can be diagnostic, predictive, and also prognostic. Immunohistochemistry also empowers us to evaluate these markers in archival samples, including pretreatment and posttreatment biopsies.