Pituitary Disorders

Question 1

cushings syndrome

Answer 1

elevated cortisol from any source

Question 2

cushings disease

Answer 2

central/pituitary Cushing’s from elevated pituitary ACTH

Question 3

Cushing’s syndrome specific findings

Answer 3

• thin skin/purple striae
• supraclavicular fat pads
• proximal muscle weakness

Question 4

diagnosis of cushing’s syndrome

Answer 4

• screen 24 hr urine free cort and/or late night salivary cort
• if elevated or high suspicion, use low dose dex suppression to confirm Cushing’s, check ACTH at the same time
• if suppression inadequate, look at ACTH (if ACTH low, then adrenal gland to blame, if ACTH normal or high then pituitary or ectopic to blame –> use high dose dex to differentiate pituitary vs. ectopic)

Question 5

Cushing’s tx

Answer 5

• 1st line = surgery
• 2nd line = radiation, preferable gamma knife
• 3rd line = medications that decrease synth of cort
• for large masses an evaluation for loss of other pituitary functions is appropriate

Question 6

acromegaly tx

Answer 6

• 1st line = surgery
• 2nd line = radiation, preferable gamma knife
• 3rd line = medications that either decrease GH release or block binding to receptor
• for large masses, evaluation for loss of other pituitary function is necessary

Question 7

Acromegaly

Answer 7

• rare
• insidious onset
• characterized by coarse features, enlarged tongue, deep voice, large joints in hands. Usually, you need to look at old pictures to make a dx
• high IGF-1

Question 8

hyperprolactinemia tx

Answer 8

• dopamine agonist therapy (stimulation of dopamine), bromocriptine (safe in preg, long-term), carbergoline (longer acting)
• follow up MRI to check for shrinkage of mass
• when there is high PRL, it suppresses E

Question 9

panhypopituitarism

Answer 9

-problem producing multiple pituitary hormones

Question 10

tx of panhypopituitarism

Answer 10

• remove or shrink the mass
• all hormones need to be replaced
• steroids FIRST for adrenal insuff
• after 2 days can follow with thyroid and T therapy

Question 11

diabetes insipidus

Answer 11

• not very common
• can be seen isolated. it is rarely associated with anterior pituitary function loss
• usually need to do water deprivation
• vasopression challenge tells us where the problem is

Question 12

vasopressin challenge

Answer 12

• testing for diabetes insipidus
• 5mcg SQ x one
• if urine osm increases by >50% then the kidneys are responding and the DI is central
• if urine osm doesnt change, kidneys DONT respond and the DI is nephrogenic

Question 13

extremely rare pituitary cases

Answer 13

• gonadotrope (FSH/LH) secreting masses

- TSH secreting mass leading to increased free T4