CUSHING SYNDROME   66A

A 35-year-old woman has hypertension of recent onset. Review of systems reveals several months of weight gain and menstrual irregularity. On examination, she is obese, with a plethoric appearance. The blood pressure is 165/98 mm Hg. There are prominent purplish striae over the abdomen and multiple bruises over both lower legs. The patient’s provider entertains a diagnosis of hypercortisolism (Cushing syndrome).

What are the salient features of this patient’s problem? How do you think through her problem?

Salient features: Hypertension; weight gain; menstrual irregularity (indicating pituitary dysfunction); purple striae on the abdomen

How to think through: Is a complete workup for secondary causes of hypertension appropriate in every new hypertension diagnosis? (No; 30% of U.S. adults have hypertension, and most have idiopathic “essential hypertension.” Also, tests such as endocrine assays have imperfect sensitivity and specificity. Look for symptoms and signs of secondary causes and then direct the diagnostic workup accordingly. Also, evaluate fully all cases of early onset and refractory hypertension.) In this case, evidence gathered by history and physical examination points to a possible secondary cause. In addition to her cushingoid appearance, weight gain, irregular menses, striae, and bruising, what other manifestations of cortisol excess should be sought in this patient? (Proximal muscle weakness, mood lability, elevated fasting glucose.) How do we establish that she has elevated cortisol levels or Cushing syndrome? (24-hour urine cortisol. Low-dose dexamethasone suppression test.) What test establishes the broad categories of possible causes of Cushing syndrome? (Plasma adrenocorticotropic hormone [ACTH] level. ACTH levels are abnormally high in ACTH-dependent processes such as hypothalamic cortisol-releasing hormone [CRH] hypersecretion, ACTH-producing pituitary adenoma, and ectopic ACTH-producing tumor. Plasma ACTH levels are low in ACTH-independent processes such as adrenal adenoma or exogenous corticosteroid use.) Which of these is the most common cause of Cushing disease? (Cushing disease implies an ACTH-producing pituitary adenoma.)

CUSHING SYNDROME   66B

What are the essentials of diagnosis and general considerations regarding Cushing syndrome?

Essentials of Diagnosis

Central obesity, muscle wasting, thin skin, psychological changes, hirsutism, purple striae

Osteoporosis, hypertension, poor wound healing

Hyperglycemia, leukocytosis, lymphocytopenia, hypokalemia, glycosuria

Elevated serum cortisol and urinary free cortisol; lack of normal suppression by dexamethasone

General Considerations

Cushing syndrome refers to manifestations of excessive corticosteroids, commonly caused by supraphysiologic doses of corticosteroid drugs.

Cushing disease is caused by ACTH hypersecretion by the pituitary, often from an adenoma.

ACTH-secreting pituitary adenoma (Cushing disease) is more than three times more common in women than men.

Stay updated, free articles. Join our Telegram channel

Join