Adrenal Cortex

Question 1

Serum cortisol secretion undergoes diurnal variation:

• Trough
• Peak

Answer 1

• Trough - Midnight (12 AM)

- Peak - 8 AM

Question 2

Cushing syndrome is characterized not only by Elevated Serum Cortisol, but also loss of what?

Answer 2

Diurnal Variation

Question 3

Elevated Midnight Serum Cortisol is highly suggestive of what?

Answer 3

Cushing Syndrome

Question 4

Low 8 AM serum Cortisol is highly suggestive of what?

Answer 4

Adrenal Insufficiency

Question 5

Urine Free Cortisol Test:

• Collection
• Measures (2)

Answer 5

24 hour urine collection

• Free (unbound) serum Cortisol
• Independent of time of day considerations

Question 6

Dexamethasone Suppression Test results in Normal Endocrine function.

Answer 6

Dose of Dexamethasone will

-Supress both ACTH and Cortisol

Question 7

Low-Dose Dexamethasone Suppression Test (DST):
-2 Forms

*Answers what question?

Answer 7

• Rapid (overnight) DST
• Standard (2 day) DST
• Does the Pt. have Cushing Syndrome (Hypercortisolism)?
• If impaired suppression - Yes

Question 8

What question does the High-Dose Dexamethasone Suppression Test (DST) answer?

Answer 8

Is the Cushing syndrome caused by a Pituitary Adenoma

Cushing Disease

Question 9

High-Dose Dexamethasone Suppression Test (DST):

• Suppression
• Nonsuppression (2)

Answer 9

Suppression
-Pituitary Adenoma (Cushing Disease)

Nonsuppression*:

• Ectopic ACTH production (tumor)
• Primary Adrenal Hypercortisolism

*distinguished by plasma ACTH measurements

Question 10

What other test is used to determine the cause of Cushing Syndrome?

Answer 10

Cortisol Releasing Hormone (CRH) stimulation test

Question 11

Cortisol Releasing Hormone (CRH) stimulation test:

• Exaggerated Elevation of ACTH/Cortisol
• No response (2)

Answer 11

Exaggerated Elevation of ACTH/Cortisol:
-Pituitary Adenoma

No Response:

• Adrenal Tumors
• Ectopic ACTH

Question 12

Diagnosis of Cushing Syndrome (Hypercortisolism) requires the demonstration of persistent hypercortisolism. What are the 3 recommended Screening Tests?

Answer 12

• Low-Dose DST
• 24hr Urinary Free Cortisol
• Midnight Salivary or Serum Cortisol

Question 13

ACTH-Dependent Cushing Syndrome is further evaluated by what tests? (3)

Answer 13

• Bilateral Inferior Petrosal Sinus Sampling (BIPSS)
• High-Dose DST
• CRH stimulation test

Question 14

ACTH-Independent Cushing Syndrome:

• Must Exclude?
• Requires

Answer 14

• Surreptitious Glucocorticoid administration

- Adrenal Imaging

Question 15

Most common cause of Cushing Syndrome in developed world.

Answer 15

Iatrogenic

-Corticosteroids for Tx of Inflammatory Disease

Question 16

Cushing Disease is usually found in association with what?

Answer 16

Pituitary Microadenoma (<1.0 cm)
-Basophilic cells (Corticotrophs)

Question 17

What neoplasms are associated with Ectopic ACTH production? (7)

Answer 17

• Small Cell Lung Cancer
• Lung Carcinoid
• Pancreatic Endocrine Tumors
• Non-Small Cell Lung Cancer
• Thymic Tumors
• Medullary Thyroid Carcinoma
• Breast Cancer

Question 18

Primary Adrenal Hypercortisolism may be due to? (3)

Answer 18

• Adrenal Adenoma
• Adrenal Carcinoma
• Bilateral Adrenal Hyperplasia

Question 19

What are the Systemic Effects of Cushing Syndrome? (6)

Answer 19

• Hyperglycemia
• Hypokalemia
• Protein Catabolism
• Osteoporosis
• Centripetal Fat Deposition
• Skin Thinning w/ Striae

Question 20

What are causes of Pseudo-Cushing syndrome? (4)

Answer 20

• Major Depression
• Anorexia Nervosa
• Alcoholism
• Pregnancy

Question 21

Diagnosis Criteria for Addison Disease (Primary Adrenal Insufficiency). (2)

Answer 21

• Low 8AM serum Cortisol (and/or)

- Blunted increase in Cortisol following Cosyntropin Stimulation

Question 22

The ACTH level is used to guide further evaluation of Addison Disease.

• Elevated ACTH
• Next tests

Answer 22

Elevated ACTH = Primary Adrenal Insufficiency

• Autoantibody studies (and/or)
• Adrenal Imaging

Question 23

The ACTH level is used to guide further evaluation of Addison Disease.
-Normal or Low ACTH (2)

Answer 23

WNL/Low ACTH - Secondary Adrenal Insufficiency

• Pituitary Pathology
• Exogenous Glucocorticoids

Question 24

Most common cause of Addison’s Disease (Primary Adrenal Insufficiency):

*Historically

Answer 24

Autoimmunity

*Tuberculosis - primary destruction of adrenal gland by granulomatous disease

Question 25

What are the characteristic findings in Addisonian Crisis? (6)

Answer 25

- Altered Mental Status - Hypotension - Hypoglycemia - Hyponatremia - Hyperkalemia - Metabolic Acidosis

Question 26

Clinical Features of Addison's Disease (Primary Adrenal Insufficiency)? (7)

Answer 26

- Fatigue - Weakness - Weight Loss - Mood Alteration - Postural Hypotension - Skin Hyperpigmentation - Hypoglycemia

Question 27

Most cases of Secondary Adrenal Insufficiency is cause by Exogenous Glucocorticoids, which lead to what?

Answer 27

Irreversible (or slowly reversible) suppression of endogenous ACTH production

Question 28

Why is Secondary Adrenal Insufficiency not as severe as Addision's Disease

Answer 28

Minearlocorticoid production is maintained in Secondary by the Renin-Angiotensin System

Question 29

What is the finding in Secondary Adrenal Insufficiency? (1) | -What findings are NOT seen

Answer 29

Mild Hyponatremia - Hyperkalemia is Absent - Hyperpigmentation is NOT seen

Question 30

Hyperaldosteronism is also known as what?

Answer 30

Conn Syndrome

Question 31

Conn Syndrome (Hyperaldosteronism) is usually caused by what? (2)

Answer 31

- Adrenal Adenoma | - Bilateral Adrenal Hyperplasia

Question 32

``` Conn Syndrome (Hyperaldosteronism): -Findings (3) ```

Answer 32

- HTN - Hypokalemia - Metabolic Alkalosis

Question 33

What is the best screening test for Conn Syndrome (Hyperaldosteronism)? *Confirmatory Test

Answer 33

Plasma Aldosterone Concentration (PAC) to Plasma Renin Activity (PRA) -[PAC:PRA] *24 hour urinary Aldosterone level

Question 34

Secondary Hyperaldosteronisms is seen in what state? | -Causes (2)

Answer 34

Hyperreninemic States - Renal Artery Stenosis - Jutaglomerular Cell Tumor of Kidney (Renin Producing)

Question 35

What is the most common cause of Congenital Adrenal Hyperplasia (CAH)? -2nd MC

Answer 35

21-Hydroxylase deficiency | -11-Hydroxylase deficiency

Question 36

Where is the gene for 21-Hydroxylase found? (2)

Answer 36

``` Chromosome 6 (6p21.3) -within HLA complex ```

Question 37

What are the characteristic serum labs seen in CAH? (6)

Answer 37

- 17-Hydroxyprogesterone (High) - Cortisol (Low) - ACTH (High) - Androgens (High) - 17-ketosteroids (High) - Aldosterone (Low)

Question 38

21-Hydroxylase deficiency Vs. 11-Hydroxylase deficiency - Both show Adrenal Hyperplasia and Virilzation. What findings differ between the two?

Answer 38

21-Hydroxylase deficiency -Salt Wasting 11-Hydroxylase deficiency -HTN