Endo: Pit Dysf (PRL, GH, Adrenal) Flashcards
Compare central and peripheral hormone disorders.
Central: problem is in hypothalamus or pituitary gland
Peripheral: problem is in end organ (eg. adrenal, ovaries, etc)
What is a Rathke’s cleft cyst?
What are the symptoms?
- Rathke’s cleft cyst is a remnant of Rathke’s pouch
- Asymptomatic
Is craniopharyngioma malignant or benign?
Craniopharyngiomas are benign, slow-growing tumors (Grade I)
Describe the type of craniopharyngioma most common in children.
(Name, CT feature, 3 sx)
- Adamantinomatous
- Calcifications on CT
- Sx: growth failure, delayed puberty, tunnel vision
An adult walks in with headache, vision changes, and hypopituitary function.
What is one possible neoplasm?
- Papillary craniopharyngioma
Are pituitary adenomas usually sporadic or inherited?
Do they always produce hormones?
Pituitary adenomas are usually sporadic.
They may or may not produce hormones
A patient presents with headaches, bitemporal hemianopsia, opthalmoplegia, and pituitary hormone deficits.
Why are these symptoms occuring?
- Pt has a pituitary tumor
- Headache, visual field deficits, and cranial nerve palsies are due to mass effect (tumor pressing on other structures)
What is the order in which pituitary hormones will decrease with a pituitary adenoma?
Gonna - GH
Lose - LH/FSH
The - TSH
Anterior - ACTH
Pituitary - PRL
(or, “go look for the adenoma please”)
Describe the HPA axis for growth hormone (4)
- Hypothalamus releases GHRH
- GHRH stimulates GH release by anterior pituitary somatotrophs
- GH stimulates liver to release IGF-1
*Hypothalamus can also release Somatostatin, which inhibits anterior pituitary release of GH
What is the effect of glucose on GH release?
Effect of sleep?
Effect of exercise?
Effect of puberty?
- Glucose suppresses GH release
- Sleep, exercise, and puberty all increase GH release
Name 2 effects of IGF-1
- Increased muscle growth
- Increased bone growth
Compare the onset and signs of gigantism and acromegaly
- Gigantism: GH excess before puberty
- Tall
- Acromegaly: GH excess after puberty
- Increased hand, feet, head size
How do you diagnose GH excess?
Why do we use this method?
- Increased IGF-1 level
- Don’t measure GH directly b/c GH has a short half-life and is released in pulsatile waves, so difficult to get a representative measurement
What is the medical treatment of acromegaly and gigantism?
Octreotide (somatostatin analog)
What are the symptoms of GH deficiency in adults? (4)
Is this always pathalogic?
GH deficiency causes
- Increased fat
- Decreased muscle
- Decreased bone density, fractures
- Increased cholesterol
*All occur with normal aging, too
What is the treatment of GH deficiency in adults?
GH can be administered, but its use is controversial
How do you diagnose GH deficiency? (2)
- Low IGF-1
- Induce hypoglycemia with insulin and see if GH rises (it should)
What hormone released by the hypothalamus stimulates PRL release from ant pituitary?
Thyroid releasing hormone (TRH)
A woman presents with galactorrhea, menstrual irregularity, and infertility.
What tumor could cause this?
These are all symptoms of prolactinoma.
A male presents with visual field abnormalities, headache, opthalmoplegia, and impotence.
What tumor could cause this?
Prolactinoma
Men tend to have large tumors, so sx largely due to mass effects
Bromocriptine: MOA, use
- MOA: Dopamine agonist
-
Use: Tx for prolactinoma
- Cabergoline is first line, but bromocriptine is better if going to become pregnant
What agent is first line in treatment of prolactinoma?
Cabergoline, a dopamine agonist
What are the symptoms of PRL deficiency in men and women? (1 each)
- Women: failed lactation after childbirth
- Men: no known effects
What are the effects of cortisol?
A BIG FIB
- Appetite increased
- Blood pressure increased
- Insulin resistance
- Gluconeogenesis and lipolysis increased
- Fibroblast suppression
- Inflammation suppression
- Bone formation decreased
