Painting the path to precision: unraveling endocrine tumors with immunohistochemistry

Abstract

While morphological assessment remains the primary cornerstone in tumor diagnostics, immunohistochemical (IHC) analyses hold immense value in surgical pathology. This is particularly true in endocrine pathology, which encompasses a multitude of tumors from various organs, often presenting with several morphological mimics. In many cases, IHC proves to be invaluable for practicing pathologists in reaching accurate diagnoses. Furthermore, IHC plays a pivotal role in prognosticating endocrine tumors, aiding pathologists in grading and assessing the risk associated with these lesions. Additionally, the identification of specific markers has enabled the recognition of subsets of endocrine tumors suitable for tailored therapies. Consequently, IHC assumes a crucial role in the comprehensive management of endocrine neoplasia, encompassing diagnosis, prognostication, and treatment. This review article comprehensively explores the fundamentals of IHC in the clinical workup of endocrine and neuroendocrine tumors, with a specific emphasis on what pathologists in training should be familiar with, encompassing both its strengths and potential pitfalls.