. Author manuscript; available in PMC: 2021 Apr 2.

Published in final edited form as: Best Pract Res Clin Endocrinol Metab. 2020 Apr 2;34(2):101418. doi: 10.1016/j.beem.2020.101418

Table 1.

Classification of types of Cushing syndrome.

Etiology		Mechanism
Exogenous	Iatrogenic	Exogenous administration of supraphysiologic doses of glucocorticoids as part of therapeutic scheme for a medical condition (autoimmune, rheumatologic, malignant etc)
Endogenous	ACTH-dependent	Pituitary ACTH secreting tumors (ACTH-secreting pituitary adenomas or carcinomas, pituitary blastomas)
	ACTH-dependent	Ectopic ACTH and/or CRH secretion (bronchial, thymic, or pancreatic neuroendocrine tumors, and others)
	ACTH-independent	Adrenocortical carcinomas
		Cortisol-Producing Adrenocortical adenomas (CPAs)
		Bilateral adrenocortical hyperplasia (BAH) - Micronodular (most nodules < 1cm) • Pigmented • Primary Pigmented Nodular Adrenocortical Disease (PPNAD) in the context of Carney complex • Isolated Primary Pigmented Nodular Adrenocortical Disease (PPNAD) • Isolated Micronodular Adrenocortical Disease (iMAD) - Macronodular (most nodules > 1cm) • Bilateral Macroadenomatous hyperplasia (BMAH): adenomas with internodular atrophy • Massive Macronodular Adrenocortical Disease (MMAD): adenomas with internodular hyperplasia