Adrenal Gland Disorders

Question 1

Adrenal Gland

Answer 1

Def:
* Gland sits in top of kidneys

• Division: (it gets better as you go deeper) (SALT, SUGAR, SEX)
  1. Adrenal cortex
     
     • • Zona Glamerulosa: secretes Aldosterone (SALT)
     • • Zona Fasiculata: secretes cortisol (SUGAR)
     • • Zona Reticularis: secretes androgen (testosterone) (SEX)
  2. Adrenal Medulla
     
     • • secretes catecholamine via Chromaffin cells (epinephrine & Norepinephrine)

Question 2

Cushing syndrome

Answer 2

Def:

• Excess cortisol (some ACTH-dependent & some ACTH-independent)
• more common in women

Caused by:

1. Exogenous factors:
   * glucocorticoids
2. Endogenous factors:
   
   2. 1 decreased ACTH
      
      • Primary adrenal disease
   3. 2 increased ACTH
      
      • Pituitary adenoma (Cushing’s disease)
      • para-neoplastic (small cell carcinoma)
      • CRF-releasing tumor

Note-extend:
Caused by:
* Lung tumor that secretes ACTH
* Cushing disease that have anterior pituitary tumor that secretes ACTH
* Too much use of steroids supplement (ingestion) producing cortisol
* Primary tumor of adrenal gland producing too much cortisol

Sign/ symptoms:

• HTN + Diabetes + Obese
• Moon facies (bad acne)
• Truncal/abdomenal obesity
• Buffalo hump
• Purple striding (stretch mark on abdomen)
• osteoporosis
• amenorrhea
• immune suppression
• decreased insulin sensitivity

Diagnosis:

• sign & symptoms of Cushing’s
• Low-then-High investigation:
  * * low-dose dexamethasone suppression test
  * **(dexamethasone suppress cortisol normally, but here will fail to do so: gives you Cushing’s syndrome)
  * ** confirm Cushing’s syndrome with additional tests: 24h urine cortisol or late-night salivary cortisol
  * * ACTH
  * ** Normal ACTH: adrenal tumor (primary hypercortisolism) —> CT/MRI of abdomen & resection
  * ** elevated ACTH:
  * ** High-dose dexamethasone suppression
  * ** positive-suppression: anterior pituitary tumor = Cushing’s disease —> resect
  * ** fail to suppress: Ectopic tumor —> Pan Scan ( CT of chest & pelvis help you to find it)

Question 3

Addison’s disease

Answer 3

Def:

• too little cortisol
• adrenal insufficiency

Caused by:

• is it problem with anterior pituitary gland (that secretes ACTH) ? (Renal-angiotensin system intact)
• is it a problem with adrenal gland ( that secretes cortisol) ? (Problem with aldosterone too)
• due to problem with:
  
  • • autoimmune
  • • TB
  • • anterior pituitary

Sign/symptoms:

• Acute: lose both cortisol & aldosterone (hypotensive, N/V, Coma)
• chronic: orthostatic hypotension, hyperpigmentation, low sodium & high K

General:

• deficiency in cortisol & aldosterone
• skin hyperpigmentation (increased POMC)
• hypotension
• hyperkalemia
• acidosis
• addisonian crisis
  
  • *assessment: severe symptoms + shock
  • • intervention:
      
      1. High-dose hydrocortisone
      2. Large volume of IV- fluid
      3. Insulin with dextrose
      4. Kayexalate (Sodium polystyrene sulfonate) (treat high K+ level in blood)
      5. Loop or thiazide diuretics

Diagnosis:
* sign & symptoms of Addison’s
* investigation:
** Cortisol (AM)
**Normal: rule out the disease
** low: Addison’s
*** confirm it with Cosyntropin-stimulation test ( give patient ACTH)
** elevated cortisol: problem with anterior pituitary —> MRI + Replace cortisol
** Cortisol not elevated: problem with adrenal gland (Addison’s disease) —> CT/MRI + replace
both cortisol & aldosterone

Treatment:
* exogenous cortisol

Question 4

Conn’s syndrome

Answer 4

Def:
* too much aldosterone

Caused by:

• problem with aldosterone ? Primary tumor in adrenal gland
• problem with renal artery ? Renal vascular hypertension
  * * fibromuscular dysplasia (FMD) (young women)
  * * atherosclerotic disease (AS) (old men)

Sign/symptoms:

• HTN + Hypokalemia
• secondary HTN = refractory to 2 or 3 medication

Diagnosis:

• sing/symptoms of Conn’s
• investigation:
  
  • • aldo: renin ratio
      
      • ** aldo not elevated/ renin not elevated: mimicker (congenital adrenal hyperplasia, licorice ingestion)
      • ** aldo elevated/ renin elevated —> (aldo:renin ratio < 10) : renovascular HTN
        * ** FMD: STENT
        * ** AS: No STENT
      • ** aldo elevated/ renin not elevated —> (aldo: renin ratio > 30): Conn’s syndrome
        * ** confirm with (salt-suppression) —> normally aldosterone is decreased, but here it will fail
        * ** perform MRI
        * ** adrenal vein sampling before resection if tumor or no tumor presented

Question 5

Renin-Angiotensin-Aldosterone Axis ( System)

Answer 5

• RAA axis is independent of HPA axis

Pathway:

• thick ascending limb secretes Renin
• converted to Angiotensin 2
• angiotensin 2 act on adrenal gland to produce aldosterone
• aldosterone insert channel & Aquaporin- channel into collecting duct to
  
  • *reabsorb Na & expels K
  • • reabsorb H2O

This system is activated, due to

• low flow to the kidney
• to increase GFR

**if tumor is found in adrenal glad that secretes too much aldosterone ?? Lead to Conn’s Syndrome

Question 6

Pheochromocytoma

Answer 6

Def:
* catecholamine-secreting tumor

Caused by:
* tumor of the medulla of the adrenal gland that secretes too much catecholamine

Sing/symptoms:

• paroxysmal (sudden attack that comes and disappear)
• pain (headache)
• pressure (episodic HTN)
• palpitation (tachycardia)
• perspiration (sweating)
• abdominal or chest pain

Diagnosis:
* plasma-free catecholamine 
OR
* 24hr urine metanephrine or VMA 
Then:
* CT/MRI of abdomen 
* adrenal vein sampling 

Treatment:

• alpha-blockade (prevent HTN)
• beta-blockade
• then surgery to resect tumor

Intervention:

1. Surgery
2. Antihypertensive
3. Phenoxy-benzamine (alpha-blockade)
4. Metyrosine (demser) (pre-operative to control HTN)

Question 7

Incidentaloma

Answer 7

Def:
* you get a CT/MRI scan for something else, and you incidentally come cross this !!

Diagnosis:
* start with ruling out other diagnosis ( Cushing, Conn, Pheochromocytoma) with 24hr urine

Treatment:

• less than 4 cm: watch & wait
• more than 4 cm: resect