Lecture 5: Pituitary Disorders Flashcards Preview

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Flashcards in Lecture 5: Pituitary Disorders Deck (76)
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1
Q

What is the BEST imaging modality for the pituitary?

A

MRI (T1)

2
Q

Definition of HYPOpituitarism

A

Diminished or absent secretion of 1 or more pituitary hormones

3
Q

7 I’s (causes) of HYPOpituitarism

A
  1. Invasive
  2. Infarction
  3. Infiltrative
  4. Injury
  5. Immunologic
  6. Iatrogenic
  7. Isolated
4
Q

What are the 2 diseases associated w/Infarction that leads to HYPOpituitarism?

A
  1. Sheehan’s Syndrome (MC)

2. Apoplexy

5
Q

Invasive: Why are large pituitary adenomas more likely to cause hypofunction in the pituitary than small ones?

A

Large pituitary adenomas cause compression of surrounding structures –> meningiomas, lymphoma, metastatic CA, etc

6
Q

Definition of Sheehan’s Syn?

A

Bleeding into the pituitary

7
Q

Who is most likely to develop Sheehan’s syndrome

A

pregnant women in the postpartum period

8
Q

Why do lactotroph cells die in Sheehan’s syndrome? result?

A

lactotroph cells have an increased demand for blood but hemorrhage decreases the blood supply –> ischemia & necrosis

9
Q

3 Signs/Sxs of Sheenhan’s Syndrome

Who is likely to have Sxs in Sheehan’s

A
  1. Agalatorrhea (decr breastmilk production) –> dont lactate
  2. post-partum menstrual irregularities
  3. Fatigue

Usu Sheehan’s is only symptomatic in breastfeeding women

10
Q

What are the 3 diseases associated w/Infiltration that leads to HYPOpituitarism?

A
  1. Sarcoidosis
  2. Hemochromatosis
  3. Langerhan’s Histicytosis
11
Q

What types of Injuries can cause HYPOpituatrism?

A

head trauma, physical abuse (subdural hematomas)

12
Q

What dz is associated w/Immunologic that leads to HYPOpituitarism?

A

Lymphocytic Hypohysitis

  • Autoimmune d/o –> destruction of AP
13
Q

What 3 things associated w/Iatrogenic that leads to HYPOpituitarism?

A
  1. Surgery &
  2. Radiation therapy
  3. infections
14
Q

What is the progression of hormone defic seen in HYPOpituitarism from early to late?

A
GH
FSH, LH
TSH
ACTH
PRL 

“Good Fucking Losers TAP out”

15
Q

If the pituitary is failing –> HYPOpituitarism what do you expect the levels of pituitary hormones to be

A

pituitary secreting hormones will be LOW

AP failure –> cant release its hormones
- LOW TSH, LH, FSH, ACTH

16
Q

If a gland is failing (ovaries) –> HYPOpituitarism what do you expect the levels of pituitary hormones to be

A

pituitary secreting hormones will be HIGH

ovaries fail –> less neg feedback on hypothalamus –> more AP stimulation –> HIGH LH, FSH, etc

17
Q

Dx test for HYPOpituitary function?

When is this test not done

What diseases/ disorders is it used to Dx?

A

ACTH Stimulation Test

NOT done in eval thyroid or gonadotropin failure (ovaries)

Used to Dx Adrenal Insufficiency & GH Defic

18
Q

How is the ACTH stimulation test done? (what is given and what do you measure/when)

A

Give ACTH (Cosyntropin) –> measure cortisol levels 30-60 min later

19
Q

In PRIMARY Adrenal Insufficiency (adrenal gland failure) what do you expect the Cortisol, Aldosterone, ACTH baseline levels to be?

A

Cortisol & Aldost is low b/c adrenals failing and cant releases them –> less negative feedback on Hypothal –> upreg CRH –> incr ACTH

Baseline ACTH is HIGH

20
Q

In PRIMARY CENTRAL Adrenal Insufficiency (pituitary or hypothal failure) what do you expect the Cortisol, Aldosterone, ACTH baseline levels to be?

A

Hypothal/pituit fails –> lows levels of ACTH at baseline
but when give ACTH –> adrenals to rel cortisol and aldost

Cortisol & aldost = normal

21
Q

(General) Tx for HYPOpituitarism?

A

Hormone replacement

  • give them whatever they are defic in
22
Q

Tx for HYPOpituitarism if:

  • ACTH defic
  • TSH defic
  • Gonadotropin defic
  • GH defic
A
  • ACTH defic –> Glucocorticoids (Hydrocortisone, Prednisone)
  • TSH defic –> Levo
  • Gonadotropin defic –> estrogen, progesterone, testosterone
  • GH defic –> GH
23
Q

If you suspect Adrenal Insufficiency AND hypopituitarism why must you give glucocorticoids before Levothyroixine?

A

Opposite order (Levo then glucocorticoids) –> adrenal crisis

(T4 –> less negative feedback on hypothalamus –> more CRH –> more aCTH –> more cortisol)

24
Q

How is GH defic PRIMARILY diagnosed?

Other test helpful in Dx?

A

Clinically - using height/wt chart comparisons

GH stim test can be helpful for Dx

25
Q

What kids require eval for GH defic? (3 situations)

A
  1. Kids w/short stature < 2.5 SD below mean
  2. Height velocity < 25th percentile
  3. evid of hypothalamic-pituitary dysfunction
26
Q

3 things assoc w/COMPLETE GHDefic?

A
  1. Growth failure
  2. Delayed bone age
  3. VERY LOW hormone levels (GH, IGF-1, IGFBP-3)
27
Q

Tx for GH defic?

A

GH

28
Q

Are most pituitary adenomas benign or malignant?

Micro or macro?

A

Most are benign and MICROadenomas

29
Q

What does functional vs non-functional adenoma means?

A

functional - adenoma hypersecretes hormone(s)

non-functional - adenoma does NOT secrete hormones

30
Q

If an adenoma is compressive what mass effect sxs can it cause?

A
  • HA

- optic chiasm mass effect –> bitempotemporal hemianopsia

31
Q

what is bitemporal hemianposia

A

tunnel vision –> cant see out on periphery

32
Q

What is the MC cell type for pituitary adenomas? what does it secrete?

A

MC = lactotrophs –> secrete PRL

33
Q

Definition of prolactinoma

A

BENIGN tumor of the lactotroph cells –> hypersecretes PRL

34
Q

Define size difference b/t MACRO vs MICROadenoma

note: higher levels of PRL –> larger tumor

A

MACROadenoma is > 10mm or 1 cm

MICROadenoma is < 10mm or 1 cm

35
Q

Sxs of prolactinoma in women?

Men?

A

F: Galactorrhea, amenorrhea, menstrual irreg

Men: ED/impotence, gynecomastia

Both: decr libido, infertility

36
Q

What inhibits PRL secretion?

A

DA

37
Q

What type of medication is used to Tx prolactinomas (OR ANY OTHER PITUITARY ADENOMA)? specific names of 2 drugs?

A

DA agonists

  • Bromocriptine
  • Cabergoline
38
Q

Name of surgery for Prolactinomas (of any type)?

A

Transsphenoidal surg

39
Q

Criteria to perform gamma-knife radiation therapy on prolactinoma?

A

Tumor must be at least 5 mm from optic chiasm

40
Q

Other than PRFs what is the other stimulatory factor for PRL rel?

A

TRH!!

41
Q

How does hypothyroidism lead to hyperprolactinemia

A

Hypothyroidism –> low T3/T4 –> less neg feedback on hypothal –> more TRH rel –> more PRL rel

TRH & PRFs are stimulators for PRL

42
Q

What is a somatotropinoma

A

GH secreting pituitary adenoma

43
Q

How does acromegaly differ from gigantism in regards to linear bone growth?

A

Acromegaly - NO linear bone growth (epiphyseal plates already fused in adulthood)

Gigantism - YES linear bone growth

44
Q

What does GH stimulate in the liver than leads to most manif of acromegaly?

A

GH stimulates IGF-1 in the liver

45
Q

Screening test for acromegaly? Result?

A

IGF-1 - will be increased

46
Q

Dx test for acromegaly? Results?

A

GLUCOSE suppression/tolerance test

GH excess (acromegaly) –> incr Glucose DOES NOT suppress GH

47
Q

Med tx for acromegaly specifically? 2 drug names?

A

somatostatin analogs –> inhibit GH secretion

  • Octreotide, Lanreotide
48
Q

After TSS (transsphenoidal surg) which hormone levels normalize w/in hours, which takes longer?

A

GH normalizes 1st –> IGF-1 takes longer

49
Q

3 F/u for somatotropinoma/acromegaly?

A

MRI yearly

colonoscopy Q3-4 yrs (risk of polyps/CA)

CV eval

50
Q

What is an adrenocorticotropinoma?

What dz can it cause?

A

pituitary tumor secreting ACTH

that can cause Cushing’s Dz

51
Q

Difference b/t Cushing’s Dz and Syndrome

A

Cushing’s Dz –> caused by incr in ACTH from pituitary

Cushing’s Syn –> inc cortisol (less specific cause)

52
Q

5 Dx tests for Cushings

A
  1. 24 hr urinary cortisol
  2. Late nigh salivary cortisol
  3. Dexamethasone suppression test
  4. Basal ACTH level
  5. Central venous sampling
53
Q

What result do you expect for Cushing’s Dz when Dexamethasone suppression test given?

A

Give Dexamethasone –> suppression of ACTH = Cushing’s Dz

If ectopic ACTH tumor it wont supress

54
Q

What result do you expect for Cushing’s Dz when ACTH basal level tested?

A

ACTH level will be normal/increased

- b/c tumor secreting ACTH

55
Q

What result do you expect for Cushing’s Dz when ACTH basal level tested?

A

ACTH level will be normal/increased

- b/c tumor secreting ACTH

56
Q

Do gonadotropin adenomas secrete more LH or FSH?

2 syndromes/manif seen?

What subunit elevated (dx)

Only Tx?

A

FSH >LH

HYPO: pituitarism, gonadism

alpha subunit elevated

SURGERY ONLY (no meds)

57
Q

Presentation of TSH secreting adenomas? what is not present?

A

HYPERthyroidism w/goiter BUT NO exophtalmopathy

58
Q

Dx of TSH secreting adenoma:

  • what hormones elevated?
  • alpha subunit: TSH ratio?
A
  • hormones elevated –> TSH, TH (T3/4)

- alpha subunit: TSH ratio is > 1

59
Q

Cause of apoplexy?

A

hemorrhagic necrosis of tumor or pituitary gland infaraction

60
Q
Sudden onset of frontal HA
Visual acuity/field loss
Opthalamoplegia
Meningismus
N/V, Fever, AMS, HotN
A

signs of Apoplexy

61
Q

1st line Tx for apoplexy?

Why is surgery done?

A

IV dexamethasone –> decr cerebral edema

surgery –> prev permanent vision loss

62
Q

3 P’s of MEN1

Inheritance pattern?

A

Pituitary adenomas
Parathyroid adenomas
Pancreatic tumors

MEN = Auto dominant

63
Q

How is the sella turnica affected in empty sell syndrome? what is the result on the pituitary?

A

Sella turnica enlarges and fills w/CSF –> compresses/flattens the pituitary

64
Q

who is Empty Sella Syndrome MC in and what Sx do they have?

Note: Dx = MRI, No Tx

A

Middle aged obese women w/HTN

65
Q

What 2 major d/o occur in the Posterior Pituitary

A

Central Diabetes Insipidus

SIADH

66
Q

Difference b/t DI and SIADH

A
DI = defic of ADH 
SIADH = excess ADH
67
Q

Why excrete lot of dilute urine in DI?

A

decr ADH –> less H2O reabsorbed –> more urine excreted

68
Q

4 main Sxs of DI

A
  1. Polyuria –>
  2. Polydipsia
  3. Dehydration
  4. HoTN
69
Q

when do pts become clinically symptomatic w/ DI?

A

When they have decreased oral free water intake

70
Q

Labs in DI?

A

Hypernatremia, high serum osm, low urine osm

71
Q

Dx test for DI (in general)? How to do it? results expected in DI?

A

Water/fluid deprivation Test

deprive pt of water –> continued production of dilute urine in DI

72
Q

Dx for determine whether Central or Nephrogenic DI?

Results expected for Central?

A

ADH stimulation test

give ADH –> reduce urine output & incr urine osm

73
Q

Tx for Central DI?

A

DDVAP (synthetic ADH –> hormone replacement)

fluids

74
Q

Labs/volume status seen w/SIADH

A

HYPOnatremia, decr serum osm, incr urine osm (opposite of DI)

Pts are EUVOLEMIC!

75
Q

When do pts become clinically symptomatic w/SIADH

A

SIADH - symptomatic when increase oral free water intake

76
Q

Tx options (3)..mainstay?

A
  1. Tx underlying d/o
  2. Fluid restriction = mainstay
  3. ADH/AVP antagonists
    - promotes water excretion