Cushing's syndrome most commonly results from exogenous glucocorticoid use, prescribed for immune-mediated diseases such as rheumatoid arthritis and asthma, or for certain hematologic cancers. In contrast, endogenous Cushing's syndrome is rare and caused by excessive glucocorticoid production from the adrenal cortex. Within endogenous cases, the majority are ACTH-dependent, with pituitary-originating disease (Cushing’s disease) being the commonest form. The condition was first described by Harvey Cushing in 1932. The summary notes a distinction between iatrogenic Cushing's syndrome due to external steroids and endogenous forms arising from internal adrenal or pituitary sources, but does not provide data on incidence, diagnostic criteria, or treatment outcomes. If further specifics on diagnostic tests, cortisol/ACTH measurements, imaging, or novel cortisol-blockade strategies are needed, those details were not included in the provided material and would require additional sources. The piece contextualizes Cushing's syndrome within both exogenous and endogenous etiologies and highlights the historical description of Cushing's disease.
Cushing's syndrome is most frequently seen in patients on exogenous glucocorticoids (ie, steroids) for immune-related conditions (eg, rheumatoid arthritis and asthma) and specific haematological cancers. Endogenous Cushing's syndrome is rare, with the excess glucocorticoids arising from the adrenal cortex. The majority of cases are adrenocorticotropic hormone (ACTH)-dependent, most often pituitary-dependent Cushing's syndrome (Cushing's disease), which was first described by Harvey Cushing in 1932.