Cushing Syndrome

#med #disease #y2023 #endo

Presentation :

Proximal muscle weakness, facial plethora, supraclavicular or dorsocervical (“buffalo hump”) fat pads, wide (>1 cm) violaceous striae

Results from excess glucocorticoid exposure, either iatrogenic or endogenous.
- Iatrogenic is the most common from systemic, topical, intra-articular, or inhaled glucocorticoids
Endogenous is divided into:
- ACTH-dependent:
  - ACTH-secreting pituitary adenomas (Cushing disease)
  - ACTH-secreting carcinomas and carcinoid tumors
- ACTH-independent:
  - Adrenal adenomas/carcinomas
  - Exogenous glucocorticoids

First-line diagnostic studies include:
- Low dose (1mg) overnight dexamethasone suppression test (failure to suppress serum cortisol to <3 μg/dL)
- 24-hour urine cortisol level (elevated)
- Late night salivary cortisol level (elevated)
If the cortisol level is elevated (or not suppressible), obtain an ACTH level to differentiate ACTH-dependent from ACTH-independent hypercortisolism.
- If elevated: Pituitary MRI or CT
- If normal or suppressed: Adrenal CT

Surgical resection is the definitive treatment for benign and malignant cortisol-secreting adrenal tumors