The adrenal gland integrates catecholamine-producing neuroendocrine cells and
steroid-producing cells with mesenchymal origin in a structured manner under one
capsule and is a key regulator for vital bioactivity. In addition to
adrenal-specific disease, dysregulation of adrenal hormones is associated with
systemic effects, leading to undesirable metabolic and cardiovascular
consequences. Mass spectrometry imaging (MSI) technique can simultaneously
measure a broad range of biomolecules, including metabolites and hormones, which
has enabled the study of tissue metabolic and hormone alterations in adrenal and
adrenal-related diseases. Furthermore, this technique coupled with labeled
immunohistochemistry staining has enabled the study of the pathophysiological
adaptation of the adrenal gland under normal and abnormal conditions at
different molecular levels. This review discusses the recent applications of in
situ MSI in the adrenal gland. For example, the combination of formalin-fixed
paraffin-embedded tissue microarray and MSI to tissues from patient cohorts has
facilitated the discovery of clinically relevant prognostic biomolecules and
generated promising hypotheses for new sights into physiology and
pathophysiology of adrenal gland. MSI also has enabled the discovery of
clinically significant tissue molecular (i. e., biomarker) and pathway
changes in adrenal disease, particularly in adrenal tumors. In addition, MSI has
advanced the ability to optimally identify and detect adrenal gland specific
molecules. Thus, as a novel analytical methodology, MSI has provided
unprecedented capabilities for in situ tissue study.