**Question:** Pseudo-Cushing syndrome is seen in:

A. Cushing's disease
B. Exogenous corticosteroid use
C. Hyperthyroidism
D. Acromegaly

**Core Concept:**
Pseudo-Cushing syndrome refers to the clinical presentation of hypercortisolism without the presence of the typical ACTH-dependent pituitary adenoma seen in Cushing's disease (A). Instead, it results from various conditions that cause cortisol excess in a manner that mimics Cushing's disease, without the pituitary source.

**Why the Correct Answer is Right:**
B. Exogenous corticosteroid use: This option is correct as excessive administration of synthetic corticosteroids (e.g., prednisolone, hydrocortisone) can lead to pseudo-Cushing syndrome due to the suppression of the hypothalamic-pituitary-adrenal (HPA) axis, causing cortisol excess.

C. Hyperthyroidism: While excessive thyroid hormone production can lead to adrenal stress and cortisol release, it is not considered pseudo-Cushing syndrome because the primary cause remains within the thyroid gland itself (hyperthyroidism), not the adrenal glands.

D. Acromegaly: Acromegaly is a condition caused by excessive growth hormone production, not cortisol, so it does not fit the definition of pseudo-Cushing syndrome.

**Why Each Wrong Option is Incorrect:**
A. Cushing's disease: This refers to the ACTH-dependent pituitary adenoma causing Cushing's syndrome. Since it is caused by a pituitary adenoma, it is not pseudo-Cushing syndrome.

**Core Concept:**
Pseudo-Cushing syndrome is characterized by hypercortisolism without a pituitary source (ACTH-dependent adenoma), which is the case in Cushing's disease (A).

**Clinical Pearl:**
When assessing patients with suspected Cushing's syndrome, it is essential to consider the differential diagnosis of pseudo-Cushing syndrome due to exogenous corticosteroid use, hyperthyroidism, or acromegaly. This differentiation helps to target appropriate treatment strategies and avoid unnecessary pituitary surgery or radiation therapy.