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:

  1. Rx list : PRL raising?
    • suspicion: Antipsychotic DA antagonists disinhibit PRL)

❎ 2. TSH level (suspicion: hypothyroidism causes hyperprolactinemia)

❎ Normal TSH

  1. 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

Octreotide inactivates ILGF-1

❎ neg Glucose suppression 🚫 stop

f/u: sx/rad in refractory cases

Hypopituitarism

Chronic/indious (More common)

Acute 💥

Path:

  1. Infxn
  2. Infarction
  3. Iatrogenic

Pt: catastrophic loss of all of hormones

  1. Cortisol loss
    • Hypotensive 😮
    • Tachycardic 💗
  2. T4 loss
    • Lethargy & coma 🛌

Dx: Cortisol & T4 test

✏ Recognize rare ones

  1. Sheehan's:
    • Prolonged pregnancy/blood loss, infarct, then coma
  2. Apoplexy:
    • Tumor leading to obtunded, nuchal rigidity, headache 🤕

Tx: replace hormones

Path:

  1. Autoimmune
  2. Deposition disease
  3. Slow growing tumor that presses on stalk

✏ Body will sacrifice FSH and GH (less important) to make TSH ACTH
Screen Shot 2019-08-16 at 7.21.29 AM

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.
Screen Shot 2019-08-16 at 7.23.08 AM

  • Epi, Cortisol, GH should increase to correct low Glucose.
    • 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.
Screen Shot 2019-08-16 at 7.25.15 AM

  • incidental MRI finding, but Pt is totally alive 😃 🏁 Dx: Empty Sella

Tx: absolutely nothing

aka: reassure pt

Screen Shot 2019-08-16 at 7.13.16 AM