Cushing's syndrome is a hormonal disorder caused by prolonged exposure to high levels of cortisol, a stress hormone. It can occur when the body produces too much cortisol on its own or when taking corticosteroid medications. This condition can lead to a wide range of health problems, including weight gain, high blood pressure, and diabetes, significantly impacting quality of life.
Cushing's syndrome is characterized by the clinical manifestations of chronic hypercortisolism, regardless of the underlying etiology. Key differential diagnoses involve distinguishing between ACTH-dependent (pituitary adenoma, ectopic ACTH production) and ACTH-independent (adrenal adenoma, adrenal carcinoma, exogenous steroid use) causes.
| Condition | Distinguishing Feature |
|---|---|
| Obesity | Lack of characteristic physical findings like moon facies, buffalo hump, and striae; normal cortisol levels or appropriate response to dexamethasone suppression. |
| Polycystic Ovary Syndrome (PCOS) | Primarily characterized by hyperandrogenism and oligo/anovulation; normal cortisol levels or appropriate suppression. |
| Metabolic Syndrome | Overlap in features like obesity, hypertension, and dyslipidemia, but lacks the specific endocrine hallmarks of Cushing's syndrome and normal cortisol regulation. |
| Adrenal Insufficiency (Addison's Disease) | Opposite of Cushing's syndrome, characterized by cortisol deficiency, leading to fatigue, weight loss, and hyperpigmentation (in primary adrenal insufficiency). |
| Exogenous Glucocorticoid Use | History of corticosteroid medication use, which can mimic Cushing's syndrome; diagnosis confirmed by ruling out endogenous causes and appropriate monitoring of exogenous steroid levels. |
| Ectopic ACTH Syndrome (non-pituitary) | Similar presentation to Cushing's disease but often more rapid onset and severe; diagnosis relies on imaging to locate the ACTH-producing tumor (e.g., lung carcinoma). |
Management of Cushing's syndrome is tailored to the underlying etiology and aims to normalize cortisol levels. Treatment options include surgical resection of pituitary or adrenal tumors, medical therapy to inhibit cortisol synthesis or action, and radiation therapy for pituitary adenomas unresponsive to surgery.