Pituitary

Question 1

Ant Pit and Post Pit Hormones

Answer 1

Ant: GH, TSH, FH/LH, ACTH, Prolactin
Post: ADH and Oxytocin

Question 2

Causes of hypopit and its sx

Answer 2

See onenote M5 endocrine notes

Question 3

Some mechanisms of hypopit

Answer 3

Mass Effect, Compression of pit stalk etc.

Question 4

Causes of hyperprolactinemia

Answer 4

Non-exhaustive:
Pituitary Disorders: Prolactinoma (micro- or macro-).
Stalk effect (compression reducing dopamine inhibition).

Medications (Dopamine Antagonists or Depleters), IMPT:

Antipsychotics: Haloperidol, risperidone, olanzapine.
Antiemetics: Metoclopramide, domperidone.
Antihypertensives: Methyldopa, verapamil.
Others: Selective serotonin reuptake inhibitors (SSRIs), opioids, estrogens.

Systemic Conditions:
Hypothyroidism (increased TRH stimulates prolactin release).
Chronic kidney disease (reduced clearance of prolactin).
Chest wall injury (stimulates prolactin reflex arc).
Other Causes:

Stress or pregnancy.
Idiopathic hyperprolactinemia.

Question 5

Levels of prolactin

Answer 5

<2000 = Stalk effect (e.g. Non functioning pituitary macroadenoma with stalk effect, complicated by panhypopituitarism)

> 2000 = Micro or Macro prolactinoma

Question 6

Treatments

Answer 6

Txt of Prolactinoma = Dopamine agonists (Bromocriptine, Cabergoline)
Txt of other pit tumours=kiv surgery

To replace the hormones as well

Question 7

Misconceptions (IMPT to read)

Answer 7

1) Increased PRL can affect reduce GnRH
2) Gynaecomastia = imbalance between estrogen and androgen levels (e.g. low testosterone)
3) if SST is blunted in this case: possible atrophic adrenal gland, not responding to SST
4) Galactorrhea in acromegaly is typically due to prolactin co-secretion by the GH-secreting tumor or stalk effect