Endocrinology

Question 1

A women presenting with amenorrhea and galactorrhea most likely suffers from …

Answer 1

prolactinoma (microadenoma)

Question 2

A man presenting with hypogonadism, erectile dysfunction and bi-temporal hemianopia most likely suffers from …

Answer 2

prolactinoma (macroadema)

Question 3

What are the best initial tests in a pt suspected to have prolactinoma?

Answer 3

1. TSH (hypothyroid b/c elevated TRH enhance prolactin)
2. pregnancy test
3. prolactin levels
   (look for possible med/ drug hx - dopamine antagonist/ neuroleptics, H2 blockers)

Question 4

What are treatment options for prolactinoma?

Answer 4

1. dopamine agonist (carbergoline, bromocriptine)
2. surgery
3. radiation

Question 5

What is the major side effect associated with somatostatin analogues (octretide)?

Answer 5

cholestasis leading to cholecystitis

Question 6

What is the most common presentation of acromegaly in childhood?

Answer 6

Gigantism

Question 7

A pt presents with enlarged hands/feet/ mandible/ tongue, cardiomyopathy, bilateral carpal tunnel syndrome, deeper voice, hepatosplenomegaly, and menstrual problems (in females) most likely suffers from ….

Answer 7

Acromegaly (adult onset: 30’s-40’s)

elevated GH secretion from macroadenoma

Question 8

What is the best initial test for acromegaly?

Answer 8

IGF-1 level

if elevated, then confirm

Question 9

What is confirmatory test for acromegaly?

Answer 9

growth hormone level after 100g of glucose (if GH remains high, positive test)

Question 10

What two disease are associated with bilateral carpal tunnel disease?

Answer 10

1. acromegaly

2. hypothyroidism

Question 11

What are the treatment options for acromegaly in order of preference? (5)

Answer 11

1. transphenoidal surgery
2. octreotide
3. dopamine agonist (bromocriptine, cabergoline)
4. Pegvisomant (GH analogue that inhibits endogenous GH)
5. radiation

Question 12

What is the most common cause of death in a pt with acromegaly? What are other complications of acromegaly?

Answer 12

Cardiovascular disease (hypertrophic cardiomyopathy, accelerated atherosclerosis)

diabetes, visual defects from compression of chiasm, cord compression

Question 13

A pt presents with hypoglycemia, amenorrhea/ decreased libido, signs of hypothyroidism most likely suffers from …

Answer 13

hypopituitarism (loss of GH and FSH/LH first, then lose TSH and ACTH)

Question 14

What tests should be done to diagnose hypopituitarism?

Answer 14

1. GH level after hypoglycemia (insulin) or arginine infusion (no increase in GH)
2. FSH, LH, estrogen/testosterone levels
3. TSH, fT4, fT3
4. insulin tolerance test (cortisol level low)

Question 15

A pt with a history of an adenoma that was not treated who presents with confusion, headache, meningeal signs and altered mental status most likely suffers from ….

Answer 15

pituitary apoplexy

CT shows bleeding in head; medical & neurosurgical emergency

Question 16

A woman presents with inability to lactate after giving birth most likely suffers from …

Answer 16

Sheehan postpartum necrosis

symptoms can occur immediately or weeks–> months after pregnancy

Question 17

An asymptomatic patient is incidentally found to have no pituitary gland on CT or MRI and may have headaches and/or hypertension most likely suffers from ..

Answer 17

Empty Sella Syndrome

loss of diaphragmatic surface so meninges enter into sella turcica compressing pituitary to side

Question 18

A pt presents with polyuria, polydipsia, hypernatremia, increased serum osmolality, dilute urine, decreased urinary osmolality, and normal glucose level most likely suffers from ….

Answer 18

Diabetes insipidus (ADH dysfunction)

Question 19

What are causes of nephrogenic diabetes insipidus?

Answer 19

1. lithium
2. demeclocycline
3. hypercalcemia

Question 20

What is diagnostic test for diabetes insipidus?

Answer 20

water deprivation test

decreased urine osmolality and dilute urine remains

Question 21

How do you distinguish between nephrogenic and central diabetes insipidus?

Answer 21

vasopressin administration while water deprived
central (decreased ADH production): increased urine osmolality, concentrate urine
nephrogenic (renal resistance to ADH): urine remains dilute, decreased urine osmolality

Question 22

What is treatment for central diabetes insipidus?

Answer 22

desmopressin (DDAVP)

Question 23

What is treatment for nephrogenic diabetes insipidus?

Answer 23

1. thiazide diuretics

2. amiloride

Question 24

A pt with hyponatremia, concentrated urine (urine osmolality > 300), high urine sodium (>20), and no signs of edema or hypertension most likely suffers from …

Answer 24

syndrome of inappropriate secretion of ADH

SIADH

Question 25

What is treatment for SIADH?

Answer 25

1. treat underlying cause (pulmonary or CNS disease, chemo drugs, chlorpropamide, colfibrate)
2. fluid restriction (800-1000 ml/day)
3. demeclocycline (blocks ADH effects at kidney)
4. “vaptan” - V2 blockers
5. hypertonic saline (if severe symptoms from hyponatremia)

Question 26

What is the best initial test in suspected thyroid disease?

Answer 26

TSH

followed by free T3, free T4

Question 27

What test can distinguish between endogenous elevation of thyroid hormones versus exogenous?

Answer 27

thyroid binding globulin (TBG)

endo/ residual thyroid tissue after surgery: increased TBG
exo: decreased TBG

Question 28

What test can distinguish between primary hyperthryoidism and subacute thyroiditis?

Answer 28

radio-iodine uptake test
primary hyperthyroid: increased
subacute: decreased

Question 29

If pt has low TSH, high fT3, high fT4 with diffuse increase radio-iodine uptake most likely suffers from ..

Answer 29

Grave’s disease

Question 30

If pt has low TSH, high fT3, high fT4 with nodular increase radio-iodine uptake most likely suffers from ..

Answer 30

Toxic nodular goiter

Question 31

A pt has low TSH, high fT4, high fT3 with decreased radio-iodine uptake most likely suffers from …

Answer 31

Subacute thyroiditis