pituitary & hypothalamus

Question 1

what is hypopituitarism

Answer 1

low functioning pituitary gland
*either a problem with the hypothalamus upstream OR pituitary gland itself

Question 2

What are the causes of hypopituitarism

Answer 2

Hypothalamus or pituitary lesions
*pituitary adenoma

Question 3

What type of adenoma is most common cause of hypopituitarism

Answer 3

prolactinomas

Question 4

What age group is at highest risk for pituitary adenomas

Answer 4

30-40
*can be inherited

Question 5

How does hypopituitarism present

Answer 5

Headaches /visual changes (mass effect)
-fatigue, dizziness, hypotension, confusion, polydipsia

Question 6

If someone has GH deficiency, how will they present

Answer 6

short stature
micropenis
central obesity
hyperlipidemia
reduced muscle/bone mass
CV dysfunction

Question 7

If someone has a gonadotropin deficiency, how will they present

Answer 7

FSH and LH deficiency
*hypogonadism and infertility, impaired/absent puberty, sexual dysfunction, loss of secondary male characteristics

Question 8

how is hypopituitarism diagnosed

Answer 8

through evaluation of hormone levels or downstream effects
-evaluation of GH level

Question 9

How can you evaluate GH levels

Answer 9

Via stimulation testing
*no GH increase w/ exercise
*no GH increase with glucagon

Question 10

How can you test for adrenal deficiency

Answer 10

Low AM serum cortisol
Low serum ACTH
Low serum DHEA
Low ACTH w/ cosyntropin stimulation

Question 11

What type of imaging is done to assess the pituitary

Answer 11

MRI of hypothalamus

Question 12

Who will have an MRI of their hypothalamus to assess the pituitary

Answer 12

Men>16 with low LH & serum testosterone.

2+ pituitary hormone deficiencies

Persistent hyperprolactinemia

symptoms of mass effect

Question 13

What will be seen on imaging with hypopituitarism

Answer 13

Distinct mass
generalized pituitary enlargement
thickening of pituitary stalk

Question 14

How do you treat hypopituitarism

Answer 14

Resection of tumors or other masses

dopamine agonist in prolactinomas (first line)

radiation as a last line

Question 15

What are the dopamine agonists used for prolactinomas

Answer 15

bromocriptine or cabergoline

Question 16

If the pituitary gland is removed, what does the patient need to take for the rest of their life

Answer 16

-Glucocorticoid replacement (hydrocortisone)

-levothyroxine AFTER glucocorticoid initiation

-Gonadotropin replacement

-hGH replacement

Question 17

what is a pituitary adenoma

Answer 17

Benign tumor arising from any one of the pituitary cell types

*most common cause of hypo and hyperpituitarism in adults

Question 18

What are the classifications of pituitary adenomas

Answer 18

Micro vs Macro
Functioning vs Non-functioning

Question 19

What is a functioning pituitary adenoma

Answer 19

secretion of hormones by the tumor

Question 20

What is a macro adenoma

Answer 20

> 1cm diameter -> generally get mass effect and hypopituitarism

Question 21

What is the test of choice for a pituitary adenoma

Answer 21

MRI with gadolinium

Question 22

What is a secondary hormone dysfunction workup

Answer 22

Basal prolactin
insulin like growth factor
24hr urinary free cortisol
FSH & LH
Thyroid function test

Question 23

What are acidophils

Answer 23

GH
Prolactin

Question 24

What are basophils

Answer 24

TSH
LH/FSH
ACTH

Question 25

If the pituitary adenoma is small, how do you treat

Answer 25

Annual MRI to monitor *if no growth, can reduce frequency

Question 26

How do you treat a macro adenoma

Answer 26

Resection via a transsphenoidal approach +/- radiation

Question 27

What medications can inhibit a pituitary adenoma

Answer 27

Somatostatin dopamin *both inhibit

Question 28

what is the most common pituitary hormone hypersecretion syndrome

Answer 28

Hyperprolactinemia

Question 29

What are the underlying causes of hyperprolactinemia

Answer 29

Physiologic: exercise, inherited, sleep Pharmacologic: amphetamines, opioids, nicotine, TCA, SSRI Pathologic: Acromegaly, Hypothalamic disease, hypothyroidism, tumors

Question 30

What is a normal prolactin level in males

Answer 30

<20ng/mL

Question 31

What is a normal prolactin level in non-pregnant women? Pregnant?

Answer 31

<25ng/mL 40-800ng/mL

Question 32

What prolactin levels are indicative of a prolactinoma (excluding pregnancy)

Answer 32

>200ng/mL

Question 33

How do you workup hyperprlactinemia

Answer 33

Evaluate for underlying causes (test all other pituitary hormones) If no physiological change or pharmacologic cause -> MRI

Question 34

What is gigantism

Answer 34

excessive growth in childhood, prior to physical closure (long bones)

Question 35

What is acromegaly

Answer 35

excessive growth after physical closer (no long bone involvement) -hands -feet -head

Question 36

How do you test for acromegaly and gigantism

Answer 36

Random serum IGF-1 *if normal= ruled out

Question 37

How is gigantism physically differentiated from acromegaly

Answer 37

They have a tall stature and delayed puberty, where as acromegaly the bones would be wider than normal

Question 38

What is the workup for acromegaly and gigantism

Answer 38

Fasting, no exercise, and no illness -serum IGF-1 -prolactin level -Glucose -LFTs,BUN,creatinine -serum calcium -free T4 and TSH

Question 39

What kind of imaging can be done for acromegaly and gigantism

Answer 39

pituitary MRI Skull xray (enlarged sella, thick skull) Xray of hand and feet

Question 40

What will be seen on the hand and feet X-rays with acromegaly

Answer 40

tufting of phalanges (spade looking) Enlarged calcaneous

Question 41

What is the treatment of choice for acromegaly and gigantism

Answer 41

Transsphenoidal resection

Question 42

What is the most common skeletal dysplasia

Answer 42

achondroplasia

Question 43

What type of genetic disease is achondroplasia

Answer 43

Autosomal dominant fibroblast GF receptor 3 gene *if homozygous = Letha;

Question 44

What are some clinical features of achondroplasia

Answer 44

Disproportionate short stature large head delayed motor development short fingers exagg. lumbar lordosis prominent forehead

Question 45

How can achondroplasia be confirmed

Answer 45

genetic testing +FGFR3 mutation

Question 46

What complications arise from achondroplasia

Answer 46

recurrent OM OSA Obesity spinal stenosis narrow foramen magnum (can cause hydrocephalus)

Question 47

What is Diabetes insipidus

Answer 47

deficiency in ADH (vasopressin) - posterior pituitary loss of renal H2O reabsorption = polyuria

Question 48

What are the types of diabetes insipidus

Answer 48

Central (ADH deficiency) - primary cause being no lesion Nephrogenic (kidney just isn't responding to ADH)

Question 49

What is the presentation of diabetes insipidus

Answer 49

intense thirst cravings for ice water polyuria enuresis

Question 50

If urine has high volume and low specific gravity, how is it classified

Answer 50

dilute

Question 51

What testing can rule of DI

Answer 51

24hr urine collection with less that 2L collected

Question 52

How do you treat diabetes insipidus

Answer 52

DDAVP (desmopressin) Nasal, SQ or IV (nasal / oral preferred) start low and go slow

Question 53

What is SIADH

Answer 53

Inappropriate release of ADH

Question 54

Who is at increased risk for DI

Answer 54

Pituitary tumor Craniotomy head injury

Question 55

What causes SIADH

Answer 55

Central (metabolic, CNS, psychiatric, iatrogenic) Lungs (infection, mechanical, tumors- specifically small cell)

Question 56

How does SIADH present

Answer 56

decreased fluid output even with adequate or increased intake *fluid overload-> edema, hyponatrema, BP

Question 57

What would workup show with SIADH

Answer 57

Serum hyponatremia hypoosmolality increased urine sodium concentration normal thyroid/adrenal function

Question 58

What is the treatment of SIADH

Answer 58

Treat underlying causes fluid restriction*** if severe -> IV sodium chloride