pituitary & hypothalamus Flashcards
what is hypopituitarism
low functioning pituitary gland
*either a problem with the hypothalamus upstream OR pituitary gland itself
What are the causes of hypopituitarism
Hypothalamus or pituitary lesions
*pituitary adenoma
What type of adenoma is most common cause of hypopituitarism
prolactinomas
What age group is at highest risk for pituitary adenomas
30-40
*can be inherited
How does hypopituitarism present
Headaches /visual changes (mass effect)
-fatigue, dizziness, hypotension, confusion, polydipsia
If someone has GH deficiency, how will they present
short stature
micropenis
central obesity
hyperlipidemia
reduced muscle/bone mass
CV dysfunction
If someone has a gonadotropin deficiency, how will they present
FSH and LH deficiency
*hypogonadism and infertility, impaired/absent puberty, sexual dysfunction, loss of secondary male characteristics
how is hypopituitarism diagnosed
through evaluation of hormone levels or downstream effects
-evaluation of GH level
How can you evaluate GH levels
Via stimulation testing
*no GH increase w/ exercise
*no GH increase with glucagon
How can you test for adrenal deficiency
Low AM serum cortisol
Low serum ACTH
Low serum DHEA
Low ACTH w/ cosyntropin stimulation
What type of imaging is done to assess the pituitary
MRI of hypothalamus
Who will have an MRI of their hypothalamus to assess the pituitary
Men>16 with low LH & serum testosterone.
2+ pituitary hormone deficiencies
Persistent hyperprolactinemia
symptoms of mass effect
What will be seen on imaging with hypopituitarism
Distinct mass
generalized pituitary enlargement
thickening of pituitary stalk
How do you treat hypopituitarism
Resection of tumors or other masses
dopamine agonist in prolactinomas (first line)
radiation as a last line
What are the dopamine agonists used for prolactinomas
bromocriptine or cabergoline
If the pituitary gland is removed, what does the patient need to take for the rest of their life
-Glucocorticoid replacement (hydrocortisone)
-levothyroxine AFTER glucocorticoid initiation
-Gonadotropin replacement
-hGH replacement
what is a pituitary adenoma
Benign tumor arising from any one of the pituitary cell types
*most common cause of hypo and hyperpituitarism in adults
What are the classifications of pituitary adenomas
Micro vs Macro
Functioning vs Non-functioning
What is a functioning pituitary adenoma
secretion of hormones by the tumor
What is a macro adenoma
> 1cm diameter -> generally get mass effect and hypopituitarism
What is the test of choice for a pituitary adenoma
MRI with gadolinium
What is a secondary hormone dysfunction workup
Basal prolactin
insulin like growth factor
24hr urinary free cortisol
FSH & LH
Thyroid function test
What are acidophils
GH
Prolactin