Which of the following is characteristic of Cushing’s disease:
**Core Concept**
Cushing's disease is a form of Cushing's syndrome caused by excess adrenocorticotropic hormone (ACTH) production from a pituitary adenoma, leading to hypercortisolism. This results in various systemic effects, including weight gain, hypertension, and glucose intolerance.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of Cushing's disease, where ACTH stimulates the adrenal glands to produce cortisol. The excess cortisol causes a variety of clinical manifestations, including weight gain, particularly in the central region of the body, known as "moon facies" and "buffalo hump." The correct answer is also associated with the suppression of the hypothalamic-pituitary-adrenal (HPA) axis, leading to a decrease in ACTH production when exogenous corticosteroids are administered.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is more characteristic of Addison's disease, a condition caused by adrenal insufficiency.
* **Option B:** This option is incorrect because it is a feature of primary aldosteronism, a condition characterized by excess aldosterone production.
* **Option C:** This option is incorrect because it is a feature of pheochromocytoma, a type of catecholamine-secreting tumor.
**Clinical Pearl / High-Yield Fact**
The "short synacthen test" is a useful diagnostic tool for differentiating between Cushing's disease and other forms of Cushing's syndrome. It involves administering synthetic ACTH (tetracosactide) and measuring the response in cortisol production, which is typically suppressed in Cushing's disease.
**Correct Answer:** C.