Anterior Pituitary
Overview: pretty goddamn obvious
Hypothalamus secretes something
Anterior Pit responds, secretes another hormone
- ACTH
- TSH
- GH
- FSH/LH
hormone goes to Target organ, secretes something else
Things that keep you alive (order of importance)
- (Adrenal)Cortisol
- (Thyroid)T4
- (Liver)ILGF-1
- (repro) Testosterone/estrogen
- notice theres neg feedback
that has final metabolic effect
- Stress
- Met activity
- Growth
- Reproduction
- CRH.
- TRH
- GHrH
- GnRH
Hyperfunctioning tumors
⚠ Dustin warns about
- Central Hyperthyroidism (hi TSH/T4) but rare low yield.
- Diseases of FSH/LH are not important
Prolactinoma
Path: PRL secreting tumor (benign)
Pt: ♀
- amenorrhea
- galactorrhea 🥛
- microadenomas (they present early, tumors detected at small stage)
- no field cuts (bitemporal hemi)
Pt: ♂ (no breasts or periods)
- decreased libido (NBD, not worrisome)
- Macroadenomas
- visual field cuts 👀
Dx:
- Rx list : PRL raising?
- suspicion: Antipsychotic DA antagonists disinhibit PRL)
❎ 2. TSH level (suspicion: hypothyroidism causes hyperprolactinemia)
❎ Normal TSH
- PRL level (suspicion: prolactinoma)
✅ Elevated PRL
✅ antipsychotic cause: readjust dose
✅ Abnormal TSH = hypothyroidism
Tx: give Levothyroxine
Get MRI
❎ Normal PRL, must be something else
✅ pos MRI, Prolactinoma 🏁
Tx: DA agonists
❎ negative MRI, must be something else (outside scope)
capergoline > bromocriptine (side effects/dosing)
Acromegaly
⚠GH grows all cells, increases risk of Ca in other tissues
Path: GH secreting tumor (benign)
Pt: 👦🏻 kids get long bone growth, gigantism
Pt: 👨🏽 adults get
- hand, feet, face, visceral organ growth,
- glucose stimulation (diabetes)
- cause of 💀 - visceral growth, diastolic LVHF 💔HF is so common: look for
- 🎩 hats/gloves that don't fit
- coarse face/teeth 👹
❗Pt won't notice since its over long time course
Dx: ILGF-1 (somatomedin)
⚠ Not GH! Do not test that GH, dont do it!
✅ elevated ILGF-1
Glucose suppression test
✏ insulin competes w/ Epi, Cortisol, GH to lower Glucose
✏Unchanged GH under a glucose load is ✅positive test. I.e. Glucose Suppression test is the GH test
✅ pos Glucose suppression test
MRI
✅ pos MRI, Acromegaly 🏁
Tx: acrogmegaly: Sx (resect tumor)
- f/u : 🛑octreotide (somatostatin)
- if residual tissue continues damaging
- if residual tissue continues damaging
Octreotide inactivates ILGF-1
❎ neg Glucose suppression 🚫 stop
f/u: sx/rad in refractory cases
Hypopituitarism
Chronic/indious (More common)
Acute 💥
Path:
- Infxn
- Infarction
- Iatrogenic
Pt: catastrophic loss of all of hormones
- Cortisol loss
- Hypotensive 😮
- Tachycardic 💗
- T4 loss
- Lethargy & coma 🛌
Dx: Cortisol & T4 test
✏ Recognize rare ones
- Sheehan's:
- Prolonged pregnancy/blood loss, infarct, then coma
- Apoplexy:
- Tumor leading to obtunded, nuchal rigidity, headache 🤕
Tx: replace hormones
Path:
- Autoimmune
- Deposition disease
- Slow growing tumor that presses on stalk
✏ Body will sacrifice FSH and GH (less important) to make TSH ACTH
Pt: nonspecific
- decreased libido
- fatigability
- mensural cycle problems
Dx: Insulin Stimulation test
- or Vasopressin stim test
Confirm: Get MRI
✅ Pos MRI 🏁
✏ insulin load lowers blood glucose.
- Epi, Cortisol, GH should increase to correct low Glucose.
- Failure to stimulate is ✅positive test
- Failure to stimulate is ✅positive test
Again, this stimulation test is the GH test , and also cortisol
Tx: replace lost hormones
- and fix underlying disease
Tumor (sx), Autoimmune (prednisone), Sarcoid/amyloid (??)
Empty Sella
Path: anterior and posterior pituitary are still present, just not in the Sella.
- incidental MRI finding, but Pt is totally alive 😃 🏁 Dx: Empty Sella
Tx: absolutely nothing
aka: reassure pt
