What are the major features and etiologies of Cushing syndrome?

What are the major features and etiologies of Cushing syndrome?

• A. Weight loss, moon facies, hypotension; etiologies include dehydration and anorexia
• B. Weight gain, moon facies, truncal obesity, hypertension, buffalo hump; etiologies include ACTH-dependent (pituitary adenoma, ectopic ACTH) and ACTH-independent (adrenal adenoma/carcinoma)
• C. Hyperthyroid-like symptoms with heat intolerance; etiologies include autoimmune thyroiditis
• D. Hyperparathyroidism with hypercalcemia and kidney stones

Answer: (B)

Cushing syndrome is defined by excess cortisol, which drives fat redistribution and metabolic changes. The hallmark features include weight gain with a rounded face (moon facies), central (truncal) obesity, and a dorsocervical fat pad known as a buffalo hump, often accompanied by high blood pressure. These patterns come from cortisol’s effects on fat distribution, fluid retention, and vascular tone, and they are the classic presentation clinicians look for when suspecting cortisol excess. The causes fall into two broad groups: ACTH-dependent and ACTH-independent. ACTH-dependent means the adrenal cortex is being stimulated to produce cortisol by adrenocorticotropic hormone from another source, most commonly a pituitary adenoma (Cushing disease) or ectopic ACTH production from a nonpituitary tumor. ACTH-independent means cortisol is overproduced directly by the adrenal gland itself, as with an adrenal adenoma or carcinoma, with ACTH suppressed by negative feedback in that scenario. Other options describe different endocrine disorders with distinct features: Addison disease shows weight loss and hypotension from adrenal insufficiency; hyperthyroidism presents with heat intolerance and other thyrotoxic signs; primary hyperparathyroidism features hypercalcemia with kidney stones. These do not align with the cortisol-excess picture described here.

Cushing syndrome is defined by excess cortisol, which drives fat redistribution and metabolic changes. The hallmark features include weight gain with a rounded face (moon facies), central (truncal) obesity, and a dorsocervical fat pad known as a buffalo hump, often accompanied by high blood pressure. These patterns come from cortisol’s effects on fat distribution, fluid retention, and vascular tone, and they are the classic presentation clinicians look for when suspecting cortisol excess.

The causes fall into two broad groups: ACTH-dependent and ACTH-independent. ACTH-dependent means the adrenal cortex is being stimulated to produce cortisol by adrenocorticotropic hormone from another source, most commonly a pituitary adenoma (Cushing disease) or ectopic ACTH production from a nonpituitary tumor. ACTH-independent means cortisol is overproduced directly by the adrenal gland itself, as with an adrenal adenoma or carcinoma, with ACTH suppressed by negative feedback in that scenario.

Other options describe different endocrine disorders with distinct features: Addison disease shows weight loss and hypotension from adrenal insufficiency; hyperthyroidism presents with heat intolerance and other thyrotoxic signs; primary hyperparathyroidism features hypercalcemia with kidney stones. These do not align with the cortisol-excess picture described here.