Definition
A condition caused by prolonged exposure of the body to excess cortisol (glucocorticoid hormone)
Etiology
Adrenocorticotropic Hormone (ACTH)-Dependent Cushing's Syndrome
Cushing’s Disease
- Due to excessive secretion of ACTH by pituitary corticotroph tumor
Ectopic ACTH/Corticotropin-Releasing Hormone (CRH) Syndromes
- Ectopic ACTH syndrome is ectopic ACTH secretion due to small-cell lung carcinoma, associated with symptoms of hypertension, hypokalemia, edema, glucose intolerance
- Ectopic CRH syndrome is ectopic CRH secretion due mostly to bronchial carcinoid tumors
ACTH-Independent Cushing's Syndrome
Endogenous ACTH-independent Cushing’s Syndrome
- Adrenal hypersecretion due to adrenal adenoma, adrenal carcinoma, micronodular hyperplasia, macronodular hyperplasia
Exogenous ACTH-independent Cushing’s Syndrome
- Adrenal hypersecretion due to iatrogenic causes (eg drug-induced, prolonged corticosteroid use)
Signs and Symptoms
- Progressive obesity
- Facial obesity manifested as "moon" face
- Buffalo hump or dorsocervical fat pad
- Enlarged fat pads in the supraclavicular fossae
- Truncal obesity
- Generalized obesity
- Facial plethora
- Wasting in the extremities
- Thin skin
- Acne
- Easy bruising
- Violaceous striae width >1 cm
- Hyperpigmentation
- Hirsutism (in women)
- Proximal muscle weakness
- Impotency in men
- Changes in libido
- Menstrual disorders
- Depression/lethargy
- Central serous chorioretinopathy
- Recurrent fungal and/or bacterial infection
Associated Clinical Conditions
- Osteoporosis/decreased bone density
- Hypertension
- Diabetes mellitus (DM)/impaired glucose tolerance
- Hyperlipidemia
- Polycystic ovary syndrome
- Thromboembolism
- Growth hormone deficiency