Endocrine: Pituitary Disorders Flashcards
Anterior pituitary synthesizes what hormones? (6)
ACTH, GH, TSH, FSH, LH, Prolactin
The intermediate pituitary produces ____ which has what effect?
MSH, skin pigmentation
The posterior pituitary stores which homrones?
oxytocin, ADH
Which hormone of the posterior pituitary?
stimulate water reabsorption
conc. Urine
Released in response to hypertonicity
ADH
Which posterior pituitary hormone has the following characteristics?
↑ uterine contractions
Lactation: contracts milk ducts
Positive feedback mechanism
prolactin
The following S/S should be immediately concerning for…
bitemporal hemianopsia
Visual Impairment
Diplopia
HA
sellar masses (adenoma)
Sellar masses are often identified how?
incidental MRI finding
What is the size cutoff between a micro or macroadenoma?
1cm
60% of pituitary adenomas are…
prolactinomas
pituitary adenoma of gonadotrophs would have what effect on them?
non-functioning
pituitary adenoma of thyrotrophs would have what effect on them?
↑ TSH
pituitary adenoma of corticotrophs would have what effect on them?
↑ ACTH
Prolactinomas have what effect on lactotrophs?
↑ prolactin → hypogonadism
pituitary adenoma of somatotroph would have what effect on them?
↑ GH → acromegaly
How is sellar mass/adenoma diagnosed?
MRI or hormonal hypersecretion
what lab tests can be ordered to assess a sellar mass/adenoma?
serum prolactin
IGF-1 (GH assessment)
T3/T4/TSH
24 hour urine cortisol (ACTH)
Male patient presents w.
↓ libido impotence infertility gynecomastia \+/- galactorrhea
Prolactinoma
How is prolactinoma diagnosed in men?
serum prolactin > 20
MRI
A pre-menopausal woman presents w.
infertility
oligomenorrhea/amenorrhea
Galactorrhea
prolactinoma
How is prolactinoma diagnosed in pre-menopausal women?
serum prolactin > 30
MRI
A post-menopausal woman presents w.
HA
impaired vision
+/- galactorrhea
Prolactinoma
How is prolactinoma diagnosed in post-menopausal women?
Serum Prolactin > 20
MRI
Medical tx for prolactinoma…
Cabergoline (prolactin antagonist)
bromocriptine (DA agonist)
surgical tx for prolactinoma
transsphenoidal resection, +/- radiotherapy
What is the most common cause of GH excess
benign pituitary macroadenoma
the below are less common causes of…
ectopic tumor, MEN Type I, Neurofibromatosis
GH excess
GH excess is more or less common in children or adults?
adults
What manifestation of GH excess occurs in adults?
Acromegaly (Hands/Feet/Jaw)
acromegaly confers increased risk for…
DM/HTN/CAD Risk
GH excess manifests as ____ in children, resulting in excessive long bone growth
gigantism
Increased GH corresponds with increased ______ from the liver
IGF-1
A patient presents with…
30s
DM/HTN/CAD
+/- HF w. LV dilation
acromegaly
why is random serum GH not an accurate lab test for GH excess?
Pulsatile GH Release Thruout Day
What is the 1st test for GH excess?
serum IGF-1
The below is the gold standard dx for…
2-hour OGTT showing failure of GH decrease to < 2mcg/L
GH excess
hyperglycemia should inhibit gonadotrophs
What imaging can aid in dx of GH excess?
MRI showing pituitary tumor (95%)
Surgical tx for GH excess…
Transsphenoidal Microsurgery
Medical tx for GH excess
Octreotide/Lanreotide
Somatostatin Analogs
In GH excess Transsphenoidal Microsurgery is indicated when?
GH < 50 ng/mL, tumor ≤ 2cm
What must be monitored and when after Transsphenoidal Microsurgery for GH excess?
IGF-1 q 3-6 mo
directly linked to morbidity and mortality
These GH excess drugs are inhibitory, may decrease tumor size…
Octreotide/Lanreotide
Somatostatin Analogs
MC cause of GH deficiency?
pituitary adenoma
rare but serious cause of GH deficiency?
Sheehan syndrome
With GH deficiency, the following are increased or decreased?
Lean Body Mass
Bone Density
QOL
decreased
With GH deficiency, the following are increased or decreased?
Fat Mass
Fx risk
CVD
Mortality
Increased
Diagnosis for GH deficiency relies of ID of pituitary adenoma via..
MRI
What labs can be helpful in identifying GH deficiency? (5)
CBC CMP Lipid Panel Fasting insulin IGF-1
In addition to MRI, what imaging modality is helpful for GH deficiency?
DEXA scan
Who should be evaluated for GH deficiency?
Known hypothalamic/pituitary disease
hx of GH deficiency in childhood
What is the tx for GH deficiency?
If Childhood Onset
GH SC QD
The below are SFx of…
peripheral edema
arthralgia
paresthesia
worsening glucose tolerance
GH therapy
What type of male hypogonadism?
↓ T
↑ FSH/LH
(hypergonadotrophic hypogonadism)
primary
What type of male hypogonadism?
↓ T, FSH, LH
(hypogonadotrophic hypogonadism)
secondary
What causes primary male hypogonadism?
hypergonadotrophic hypogonadism
failure of testis
What causes secondary male hypogonadism?
hypogonadotrophic hypogonadism
defects in HPT axis
A patient presents w.
ED
hot flash
gynecomastia
infertility
↓ energy, libido, muscle mass, body hair
Male hypogonadism
sxs of estrogen excess
What 4 labs help diagnose male hypogonadism? What information do these labs give you about etiology?
Free & Total Serum Testosterone, LH, FSH
determines primary vs secondary
what f/u tests should be ordered if you determine secondary male hypogonadism?
Serum Prolactin, TSH, CBC, CMP, semen analysis, MRI
What tx regimen is recommended to treat male hypogonadism?
Testosterone IM q 2 weeks, transdermal Testosterone QD
THEN
SC Testosterone Pellets Q 3 mo
What 2 screenings should be done before initiating testosterone therapy, and what is contraindicated?
DRE & PSA (annual if T therapy initiated)
Prostate CA C/I
the below tests should be used for monitoring before or during T therapy?
Free & Total T
CBC (erythrocytosis)
Free Estradiol
DRE/PSA
during
what should always be considered with a traumatic birth?
Sheehan’s syndrome/Pan-hypopituitarism
This disease is postpartum pituitary necrosis after hypovolemia during/after childbirth
sheehan’s syndrome/pan-hypopituitarism
What is the initial sx of sheehan’s syndrome/pan-hypopituitarism?
agalactorrhea/difficulty lactating
What does the workup for pan-hypopituitarism/sheehan’s look like? (4)
H&P
full hormone workup
brain MRI
stimulation tests to exclude primary disease
What is the tx for pan-hypopituitarism/sheehan’s?
Extensive hormone replacement
1500 mg Ca2+ + 800 IU Vit. D. QD
What hormones should be administered with sheehan’s as part of extensive hormone replacement?
Levothyroxine
dexamethasone
T (for males)/Estrogen-Progestin (for females)
GH
Presentation:
Dilute Urine
Polyuria
Polydipsia, Nocturnia/Enuresis
central DI
What is a late stage finding in central DI?
hypernatremia
Central DI is most commonly by…
idiopathic ↓ ADH Release
The below is the workup for…
24 hr Urine Collection
Urine SG
Serum/Urine Osmolality
Serum Lytes Serum Glucose (r/o DM)
Desmopressin Testing
MRI
Central DI
The following test results indicate…
24 Hr. Urine Collection: > 3L/day (elevated)
Urine Osmolality: < 250 mOsm/kg (low)
Serum Osmolality: Normal to High
Serum Sodium: Normal to High
Central DI
What is 1st line tx for central DI?
Desmopressin, IN, PO, SC/IV
The below drugs can be used after 1st line drugs to treat…
Chlorpropamide
carbamazepine
thiazides
NSAIDs
Central DI
↑ ADH Release
Caused by:
Trauma, CNS Disorders, Malignancy
SIADH
4 hallmark S/S for SIADH?
Concentrated Urine
↓ Urine Volume
High Urine Osm.
Hyponatremia
The below is the workup for…
24 hr Urine Collection
Urine Sodium
Serum/Urine Osm.
Serum Lytes
CT/MRI Head
CXR ( r/o paraneoplastic syndrome)
SIADH
The below lab results indicate…
24 Hr. Urine Collection: < 2000 mL/Day (Low)
Urine Osmolality: > 1200 mOsm/Kg (High)
Serum Osmolality: Low
Serum Sodium: Low
Urine Sodium: > 40 mmol/L
SIADH
What is the 1st line tx for SIADH and with what goal?
Fluid Restriction (< 800 mL/Day)
correcting hyponatremia
In addition to fluid restriction, what can be added to tx SIADH?
PO Salt
Vasopressin receptor agonists
IV Hypertonic Saline (if severe/resistant)
What role does prolactin have in males?
work with T for increased repro
