MTB Endo

Question 1

Panhypopituitarism is caused by

Answer 1

any condition that compresses or damages the pituitary gland

Tumors

Conditions such as hemochromatosis, sarcoidosis, and histiocytosis X or infec- tion with fungi, TB, and parasites infiltrate the pituitary, destroying its func- tion.

Question 2

Panhypopituitarism presentation

Answer 2

prolactin: failure to lactate, galactorrhea, amenorrhea, gynacomastia, erectile dysfunction

FSH/LH: ammenorrhoea/erectile dysfunction, reduced libido,

GH: short stature and dwarfism, • Centralobesity
• IncreasedLDLandcholesterollevels • Reduced lean muscle mass

Question 3

Kallman Syndrome

Answer 3

• Decreased FSH and LH f r o m decreased GnRH • Anosmia

* Renal agenesis in 50%

Question 4

Panhypopituitarism Diagnostic Tests

Answer 4

TSH, LH/FSH, ACTH, (Prolactin and GH [pulsatile])
• Hyponatremia is common secondary to hypothyroidism. Potassium levels remain normal because aldosterone is not affected and aldosterone excretes potassium.
•

Question 5

panhypopituitarism Treatment

Answer 5

Replace deficient hormones with:
• Cortisone
• Thyroxine
• Testosterone and estrogen
• Recombinant human growth hormone

Replace cortisone before starting thyroxine.

Question 6

Diabetes insipidus (DI) is a decrease in either

Answer 6

the amount of ADH from the pituitary (central DI) or its effect on the kidney (nephrogenic DI).

Question 7

xxx is a classic cause of NDI.

Answer 7

Lithium

Question 8

The difference between central and nephrogenic DI is determined by the response to

Answer 8

vasopressin. In central DI, urine volume will decrease and urine osmolality will increase. With nephrogenic DI, there is no effect ofvasopressin use on urine volume or osmolality.

Question 9

Acromegaly is almost always caused by a pituitary .

Answer 9

adenoma

Question 10

Acromegaly. The best initial test is a level of

Answer 10

insulinlike growth factor (IGF-1).

Question 11

Acromegaly responds to

Answer 11

transphenoidal resection ofthe pituitary in 70% of cases.

Question 12

Acromegaly Medications:

Answer 12

• Cabergoline: Dopamine will inhibit GH release.
• Octreotide or lanreotide: Somatostatin inhibits GH release.
• Pegvisomant: A GH receptor antagonist, it inhibits IGF release from
the liver.

Question 13

Hypothyroidism leads to hyperprolac- tinemia because

Answer 13

extremely high TRH levels will stimulate prolactin secretion.

Question 14

Occasionally patients have hypothyroidism from:

Answer 14

• Dietary deficiency of iodine • Amiodarone

Question 15

Hypothyroidism

Answer 15

Bradycardia
Constipation
Weight gain
Fatigue, lethargy, coma
Decreased reflexes
Cold intolerance
Hypothermia
(hair loss, edema)

Question 16

Hyperthyroidism

Answer 16

Tachycardia, palpitations, arrhythmia (atrial fibrillation)
Diarrhea (hyperdefecation) Weight loss
Anxiety, nervousness, restlessness Hyperreflexia
Heat intolerance Fever

Question 17

Thyroid Nodules

Answer 17

These are incredibly common, and are palpable in as much as 5% of women and 1% of men. Ninety-five percent are benign (adenoma, colloid nodule, cyst). Thyroid nodules are rarely associated with clinically apparent hyperfunction- ing or hypofunctioning.

Question 18

When a patient has a nodule:

Answer 18

1. Perform thyroid function tests (TSH and T4).

2. If tests are normal, biopsy the gland.

Question 19

The most common cause of hypercalcemia is

Answer 19

primary hyperparathyroidism (PTH).

Question 20

Primary hyperparathyroidism and cancer account for xxx% of hypercalcemia patients.

Answer 20

90

Question 21

Hypercalcemia presentation

Answer 21

Acute, symptomatic hypercalcemia presents with confusion, stupor, lethargy, and constipation.
Cardiovascular
• Short QT syndrome and hypertension
Bone lesions
• Osteoporosis
Renal
• Nephrolithiasis
• Diabetes insipidus • Renal insufficiency

Question 22

Treatment

Acute hypercalcemia is treated with:

Answer 22

1. Saline hydration at high volume

2. Bisphosphonates:pamidronate,zoledronicacid

Question 23

Calcitonin

Answer 23

inhibits osteoclasts. The onset of action of calcitonin is very rapid, and it wears off rapidly. Bisphosphonates take several days to work.

Question 24

Hypocalcemia causes

Answer 24

surgery hypoparathyroidism
hypomagnesemia
renal failure The kidney converts 25 hydroxy-D to the more active 1,25 hydroxy-D.

Question 25

Low calcium =

High calcium =

Answer 25

twitchy and hyperexcitable

lethargic and slow

Question 26

Signs of neural hyperexcitability in hypocalcemia:

Answer 26

• Chvostek sign (facial nerve hyperexcitability)
• Carpopedal spasm
• Perioral numbness
• Mentalirritability
• Seizu res
• Tetany(Trousseausign)

Question 27

Primary hyperaldosteronism is

Answer 27

the autonomous overproduction of aldoste- rone despite a high pressure with a low renin activity. Eighty percent are from solitary adenoma. Most of the rest is from bilateral hyperplasia. It is rarely malignant.

Question 28

primary hyperaldosteronism =

Answer 28

High BP + hypokalemia

Question 29

Pheochromocytoma is

Answer 29

a nonmalignant lesion of the adrenal medulla autonomously overproducing catecholamines despite a high blood pressure.

Question 30

Pheochromocytoma is the answer when there is:

Answer 30

o Hypertension that is episodic in nature
o Headache
o Sweating
o Palpitations and tremor

Question 31

Pheochromocytoma treatment

Answer 31

Treatment
Phenoxybenzamine is an alpha blocker that is the best initial therapy of pheochromocytoma. Calcium channel blocker and beta blockers are used afterwards.
Pheochromocytoma is removed surgically or by laparoscopy.

Question 32

Dopamine agonists:

Answer 32

Cabergoline is better tolerated than bromocriptine.

Question 33

Cushingsyndromecanbeusedinterchangeablywiththe term

Answer 33

hypercortisolism. Cushing disease is a term used for the pituitary overproduction of ACTH.

Question 34

The 1 mg overnight dexamethasone suppression test should normally suppress the morning cortisol level. If this suppression occurs,

Answer 34

hypercortisolism can be excluded.

Question 35

High ACTH? High dexamethasone

Answer 35

• suppresses: pituitary

* does not suppress: ectopic + cancer

Question 36

Metformln is contrainidicated in those with

Answer 36

renal dysfunction because it can accumulate and cause metabolic acidosis.
Metformin works by blocking gluconeogenesis.