Guerin: Adrenal Gland Flashcards
(112 cards)
Where is cortisol made?
Zona fasciculata
Where is aldosterone made?
zona glomerulosa
Where are the sex steroids made?
Zona reticularis
What does the adrenal medulla make?
-catechohlamines like epinephrine
What does the 3 zonas (GFR) make up?
The adrenal cortex
Cushing syndrome
-excess cortisol
most common cause of cushing syndrome
-exogenous glucocorticoids
What is it called when we have excess cortisol due to too much ACTH?
- Cushing DISEASE
- pituitary probs (adenoma)
When do we most often see secretion of ectopic ACTH by nonpituitary tumors?
-small-cell carcinoma of the lung
So, what causes the ACTH-independent Cushing syndrome then?
- primary adrenal neoplasms (most commonly)
- adrenal adenoma (10%)
- adrenal carcinoma (5%): produce most profound hypercortisolism
- high cortisol, low ACTH
- primary cortical hyperplasia ia uncommon… vast majority of hyperplastic adrenals are ACTH dependent
What will we see in the adrenal glands if there is exogenous glucocorticoids?
- cortical atrophy
- suppression of ACTH… lack of stimulation of the zonae fasciculata and reticularis
When do we see diffuse hyperplasia (both glands enlarged)?
- endogenous hypercortisolism
- ACTH-dependent Cushing syndrome
- Cortex can be variably nodular
Macronodular hyperplasia
- endogenous hypercortisolism
- adrenals almost entirely replaced by prominent nodules of varying sizes
- areas between the macroscopic nodules also demonstrate evidence of microscopic nodularity
Micronodular hyperplasia
- endogenous hypercortisolism
- composed of 1-3 mm darkly pigmented (brown to black) micronudles, with atrophic intervening areas
- Pigment is through to be lipofuscin
What do adrenocortical adenomas look like?
- benign
- yellow tumors surrounded by thin or well-developed capsules
- most weigh <30 gm
- Microscopically see cells that look like normal zona fasciculata
What do adrenocortical carcinomas look like?
- LARGER than the adenomas (200-300 gm)… remember… size matters!
- Unencapsulated
Clinical course of adrenal neoplasms
- symptoms develop slowly over time
- early: htn and weight gain
- later more characteristic features: central pattern of fat deposition, moon facies, fat in the posterior neck and back
What happens to the fast twitch fibers in adrenal neoplasms?
- atrophy
- decreased muscle mass and proximal limb weakness
What happens because of the increased glucocorticoids from the adrenal neoplasm?
- hyperglycemia
- secondary diabetes
What are the catabolic effects of an adrenal neoplasm?
- loss of collagen and resorption of bones
- skin is thin, fragile, and easily bruised, poor wound healing, cutaneous striae are particularly common in abdominal area, osteoporosis
Why is there an increased risk of infection with adrenal neoplasms?
-you have immune suppression from all of the glucocorticoids probably
Diagnosis of Cushing syndrome
- increased 24 hour urine free-cortisol
- loss of normal diurnal pattern of cortisol secretion
how do we determine the cause of cushing syndrome?
- serum ACTH
- dexamethasone suppression test: urinary excretion of 17-hydroxycorticosteroids after administration of dexamethasone
out the options of pituitary cushing, ectopic ACTH, and Adrenal tumor, which of those is the only one that shows suppression from a high does of dexamethasone?
-Pituitary cushing