Pathology I Flashcards
What is Cushing’s syndrome?
Increased cortisol due to a variety of causes (p.296)
What is the number one cause of Cushing’s syndrome?
Exogenous (iatrogenic) steroids (p.296)
What is the distinguishing lab feature of iatrogenic Cushing’s syndrome?
Low ACTH (p.296)
Name three endogenous causes of Cushing’s syndrome.
Cushing’s disease (70%), ectopic ACTH production (15%), Adrenal causes (15%) (p.296)
What is Cushing’s disease?
High cortisol levels due to increased ACTH secretion from a pituitary adenoma. ACTH levels are high (p.296)
What lab finding is consistent with Cushing’s disease?
High ACTH (p.296)
What causes Cushings syndrome due to ectopic ACTH production?
Non-pituitary tissue making ACTH. ACTH is high (p.296)
Name two malignancies which are associated with ectopic ACTH production.
Small cell lung cancer, bronchial cardinoids (p.296)
What causes Cushings syndrome due to adrenal causes?
Adenoma, carcinoma, nodular adrenal hyperplasia. ACTH levels are low. (p.296)
What lab finding is consistent with Cushing’s syndrome due to ectopic ACTH production?
High ACTH (p.296)
What lab finding is consistent with Cushing’s syndrome due to adrenal causes?
Low ACTH (p.296)
What are the typical clinical findings in a patient with Cushing’s syndrome?
Hypertension, weight gain, moon facies, truncal obesity, buffalo hump, hyperglycemia (insulin resistance), skin changes (thinning, striae), osteoperosis, amenorrhea, immune suppression (p.296)
What effect does the dexamethasone suppression test have on cortisol in low doses have on a healthy individual?
Suppresses cortisol levels (p.296)
What effect does the dexamethasone suppression test have on cortisol in low doses have on a patient with an ACTH pituitary tumor?
Cortisol remains elevated (p.296)
What effect does the dexamethasone suppression test have on cortisol in low doses have on a patient with an ectopic ACTH-producing tumor?
Cortisol remains elevated (p.296)
What effect does the dexamethasone suppression test have on cortisol in low doses have on a patient with a cortisol-producing tumor?
Cortisol remains elevated (p.296)
What effect does the dexamethasone suppression test have on cortisol in high doses have on a healthy individual?
Suppresses cortisol levels (p.296)
What effect does the dexamethasone suppression test have on cortisol in high doses have on a patient with an ACTH pituitary tumor?
Suppresses cortisol levels (p.296)
What effect does the dexamethasone suppression test have on cortisol in high doses have on a patient with an ectopic ACTH-producing tumor?
Cortisol remains elevated (p.296)
What effect does the dexamethasone suppression test have on cortisol in high doses have on a patient with a cortisol-producing tumor?
Cortisol remains elevated (p.296)
Name two common presentations in a patient with an adrenocortical adenoma.
Cushing’s Syndrome; Conn’s syndrome (p.296)
Name two causes of primary hyperaldosteronism.
Adrenal hyperplasia; an aldosterone-secreting adrenal adenoma (Conn’s Syndrome). May be bilateral or unilateral (p.296)
Name four symptoms of primary hyperaldosteronism.
Hypertension, hypokalemia, metabolic alkalosis, low plasma renin (p.296)
What is the treatment for primary hyperaldosteronism?
Surgery to remove the tumor and/or spironolactone (p.296)
What is the mechanism of action of spironolactone?
A potassium sparing diuretic that works by acting as an aldosterone antagonist (p.296)
What pathologic endocrine conditions is spironolactone used to treat?
Primary and secondary hyperaldosteronism (p.296)
