Lecture 14: Pituitary Pathophysiology

Question 1

What types of diseases affect pituitary and hypothalamus?

Answer 1

1. tumors
2. infiltrative diseases
   
   • hemochromatosis
   • sarcoidosis
3. meningitis
4. trauma

Question 2

What diseases cause HYPERsecretion of pituitary hormones?

Answer 2

Only pituitary ADENOMAS can hypersecrete hormones, or fragments thereof, normally made by pituitary cells

Question 3

What diseases cause HYPOsecretion of pituitary hormones?

Answer 3

Any disease of the pituitary or hypothalamus can cause deficiency of any hormone made by anterior pituitary
Only a disease of the hypothalamus or infundibiulum can cause a deficiency of vasopressin and thereby cause diabetes insipidus

Question 4

What are examples of somatotroph adenomas?

Answer 4

1. Gigantism
2. Acromegaly
   Big hands and Neanderthal like jaw structure

Question 5

What is somatotropin?

Answer 5

Growth hormone

Question 6

What is somatostatin?

Answer 6

Shit that INHIBITS growth hormone lmao

Question 7

How do you diagnose somatotroph adenoma?

Answer 7

1. chemical confirmation
   
   • lack of suppression of growth hormone from glucose
   • elevated serum IGF-1
2. pathologic confirmation
   
   • histologic appearance of pituitary adenoma
   • immunospecific staining for growth hormone

Question 8

What are the consequences of somatotroph adenoma?

Answer 8

1. Arthritis
2. Cancer, especially of the colon, preceded by polyps
3. Cardiovascular disease
4. diabetes mellitus
5. neuropathy, including carpal tunnel syndrome
6. sleep apnea
7. mortality

Question 9

What is the treatment for somatotroph adenomas?

Answer 9

1. surgical
2. pharmacological
3. radiation

Question 10

What are the pharmacologic treatments for somatotroph adenomas?

Answer 10

1. Dopamine agonists
2. somatostatin analogs
3. Growth Hormone receptor antagonists

Question 11

What does somatostatin inhibit?

Answer 11

TSH and GH

Question 12

What is octreotide/lanreotide do?

Answer 12

It is a somatostatin analog that inhibits TSH and GH

Question 13

What is Cabergoline?

Answer 13

A drug used to reduce adenoma size

Dopamine agonist

Question 14

What is Pegvisomant? EXAM QUESTION

Answer 14

A growth hormone receptor ANTAGONIST
Decreases IGF-1 volume
Used to treat somatotrophic adenomas
Does not decrease tumor size

Question 15

What are the characteristics of lactotroph and somatotrophs?

Answer 15

They make people look funny

Question 16

What are chracteristics of ACTH, LH, FSH?

Answer 16

They are undetected physically

Question 17

What are the clinical syndromes associated with LACTOTROPH adenomas?

Answer 17

1. Premenopausal women
   
   • ammenorrhea or oligomenorrhea
   • galactorrhea
2. Postmenopausal women
   
   • neurological symptoms
3. Men
   
   • decreased libido
   • decreased fertility
   • decreased potency

Question 18

What are the causes of HYPERprolactinemia

Answer 18

1. physiologic
   
   • pregnancy
   • nursing
   • exercise
   • physical and psychological stress
2. Pathologic
   
   • lactotroph adenomas
   • dopamine receptor antagonists
   • catecholamine inhibitors
   • H2 antagonists
   • estrogens

Question 19

What can cabergoline be used for?

Answer 19

Dopamine agonist
To treat lactotroph adenomas (to inhibit prolactin)
To treat somatotroph adenomas (to inhibit GH)

Question 20

What can bromocriptine be used for?

Answer 20

D2 agonist
To treat lactotroph adenomas (to inhibit prolactin)
To treat somatotroph adenomas (to inhibit GH)

Question 21

How do you treat lactotroph adenomas?

Answer 21

Cabergoline

Bromocriptine

Question 22

What are the clinical syndromes characteristic of CORTICOtroph adenomas?

Answer 22

1. Cushing’s syndrome

2. Neurological symptoms

Question 23

What is the pharmacologic treatment of thyrotroph adenomas?

Answer 23

Somatostatin analogs
1. Reduce TSH secretion (98%)
2. Decrease adenoma size (50%)
Example: Octreotide

Question 24

What can octreotide be used for?

Answer 24

Somatostatin analog
Treat somatotroph adenoma
Treat thyrotroph adenoma

Question 25

What is the most common visual abnormality associated with a pituitary mass? EXAM QUESTION

Answer 25

Bitemporal hemianopsia (or upper visual field deficit)
Good kush and alcohol

Question 26

What are the clinical presentations of gondatotroph adenomas?

Answer 26

1. neurological symptoms
   
   • visual field impairement (bitemporal hemianopsia)
   • headaches
2. Incidental finding on MRI
3. Hormonal abnormality
   
   • premature puberty in boy
   • ovarian hyperstimulation in a premenopausal woman

Question 27

How might you expect the size of the an adenoma to be affected by Pegvisomant?

Answer 27

Would not affect the SIZE of the tumor

Because it only decreases IGF-1 in blood circulation