Pathology: Pituitary DIsorders II Flashcards Preview

Module 6: Repro/Endocrine > Pathology: Pituitary DIsorders II > Flashcards

Flashcards in Pathology: Pituitary DIsorders II Deck (19):
1


What is a pituitary adenoma?


Benign tumor of anterior pituitary cells

- May be functional or nonfunctional

2


How do nonfunctional pituitary adenomas present?


With mass effect:

- Bitemporal hemianopsia
- Hypopituitarisn
- Headache

3

What is the most common functional pituitary adenoma and how does it present?


Prolactinoma:
- Galactorrhea and amenorrhea (females)
- Decreased libido and headache (males)
 

-->This is because prolactin promotes lactation of the breasts (females), but also inhibits GnRH synthesis and release, leading to decreased FSH and LH (males and females)

4


What is the treatment for a prolactinoma?


Dopamine agonists  to inhibit prolactin secretion, leading to shrinking the tumor

and/or

surgery

5

What are the clinical features of Growth Hormone Adenomas?


- Gigantism in Children:
Linear growth of bones

- Acromegaly in adults:
Enlargement of the bones of the hands, feet and jaw
Growth of visceral organs (heart failure is most common cause of death)
Enlarged tongue

- Secondary diabetes is often present
GH decreases glucose uptake into cells

6


How are Growth Hormone Adenomas diagnosed?

Elevated GH and IGF-1 (Insulin-like Growth factor) levels

Lack of GH suppression by oral glucose

7

How are GH adenomas treated?

Treatments:

- Octreotide: Somatostatin analog that blocks response of anterior pituitary to GHRH

- Growth hormone receptor antagonists

- Surgery

 

8


What are the types of functional pituitary adenomas

Prolactinoma (*Most Common)

Growth Hormone Adenoma

ACTH cell adenomas (secrete ACTH)

TSH cell, LH-producing, and FSH-producing adenomas are very rare

9

What is hypoptuitarism?


Insufficient production of hormones by anterior pituitary

--> symptoms don't often arise until >75% of pituitary parenchyma is lost

10

What are causes of hypopituitarism?


Pituitary adenoma (adults) (either by mass effect or bleeding into the adenoma - apoplexy)

Craniopharyngioma (children)

Sheehan Syndrome

Empty sella syndrome

 

11


What is Sheehan Syndrome?


During pregnancy there is a high demand for hormone and pituitary gland doubles in size, but blood supply doesn't increase as much and can lead to infarction during birth

- Patients present with:
poor lactation
loss of pubic hair (which suggests loss of androgens, which is actually a loss of LH and FSH from the pituitary)

12

What is empty sella syndrome?  What causes it?

The sella tursica is empty and the pituitary is missing

Trauma to the pituitary and subsequent damage

Congenital defect of the sella with herniation of arachnoid and CSF into sella compressing pituitary and destroying it

13

What hormones are released from the posterior pituitary?


Oxytocin

ADH

--> both made in hypothalamus and released by posterior pituitary

14

What is central diabetes insipidus?


- ADH deficiency

--> Due to hypothalamic or posterior pituitary pathology:
- Tumor
- Truama
- infection
-Inflammation
 

15

What are clinical features of Central Diabetes Insipidus?


Polyuria and Polydipsia
- Lack ADH, can't activate aquaporins

Hypernatremia and high serum osmolality

Low urine osmolality and specific gravity

16

How is diagnosis made for Central Diabetes Insipidus? Treatment?


- Water deprivation fails to increase urine osmolality

Treat with ADH: Desmopressin

17


What is Nephrogenic Diabetes Insipidus?


Impaired renal response to ADH

- Due to inherited mutations or drugs (i.e. lithium)

- Symptoms similar to central DI, but there is no response to desmopressin

18

What is SIADH? Symptoms?


Syndrome of Inappropriate ADH

- Excessive ADH secretion

Symptoms:
Hyponatremia (cannot release water and end up diluting Na)
Low serum osmolality
Mental Status change and seizures (Hyponatremia leads to swelling of nerves and cerebral adema)

19


What are causes and treatments of SIADH?

Causes:
Ectopic production (i.e. small cell carcinoma of the lung)
CNS trauma
Pulmonary infection
Drugs (i.e. cyclophosphamide)

Treatment:
Water restriction
Demeclocycline (blocks affect of ADH)