Pituitary pathology

Question 1

MRI images what three properties of protons in magnetic fields?

Answer 1

1. T1 relaxation rate:
tendency of protons to align with magnetic field
2. T2 relaxation rate: 
loss of magnetization
3. Proton density

Question 2

most of sellar region masses are

Answer 2

85% pituitary adenomas

• equiv to WHO grade I
• treated by surgical resection
• all (except craniopharyngioma) affect middle age adults

Question 3

Pituitary adenomas Hyperfunctioning vs Nonfunctioning adenomas

Answer 3

• some are HYPERfxning and produce unregulated excess of endocrine hormones
• many are NONfxning (non secretors/weak secretors) and produce mass effect or visual disturbances due to compression of critical structures

Question 4

TTF-1

Answer 4

Thyroid transcription factor

• seen early in gestation in third ventricle
• expressed in posterior gland in adult

Question 5

Order of appearance of anterior pit. H:
8 weeks
9 weeks
12 weeks

Answer 5

8 weeks
- ACTH, GH

9 weeks
- Alpha subunit

12 weeks
- FSH, LH, TSH

Question 6

Does size of pituitary adenoma = aggressiveness?

Answer 6

No = WHO grade I

Question 7

Order of appearance of anterior pit. H:
- ACTH, GH

• Alpha subunit
• FSH, LH, TSH

Answer 7

8 weeks
- ACTH, GH

9 weeks
- Alpha subunit

12 weeks
- FSH, LH, TSH

Question 8

Which are more common in females?

Microadenomas or macroadenomas?

Answer 8

Microadenomas - females

Macroadenomas - males

Question 9

Cavernous sinus

Answer 9

contains carotid

- adenomas do not invade blood vessels, but do entrap CN III, IV, VI

Question 10

Causes of pituitary tumors

Answer 10

95% sporadic

5% familial

Question 11

4 genes associated with familial pituitary tumor syndromes

Answer 11

MEN1
CDKN1B
PRKAR1A
AIP

Question 12

do all pts with clinical features of MEN1 have a mutation in MEN1 gene?

Answer 12

No
20% of pts with features of multiple endocrine neoplasia type 1 do not have mutation in MEN1
(maybe CDKN1B)

Question 13

those have have adenomas that secrete GH may have which mutated gene?

Answer 13

AIP in familial isolated pituitary adenomas

Question 14

features that suggest an inherited pituitary tumor syndrome:

Answer 14

1. parathyroid tumors
2. pancreatic endocrine tumors
3. atrial myxomas
4. lentigines
5. Schwann-cell tumors
6. Fam hx
7. young age at onset

Question 15

Stain used to see packaging granules in pituitary adenomas

Answer 15

Synaptophysin

- but wont tell you which H are inside the granules

Question 16

Txn factors for:
ACTH
GH/TSH
PRL
FSH/LH

Answer 16

T-pit: (acts on corticotrophs)
ACHTH

Pit-1: (acts on somatotroph stem cell)
GH/
TSH
PRL

SF-1: (acts on Gonadotroph stem cell)
FSH/LH

Question 17

85% of usual ACTH adenomas are _____.

Most prolactinomas in premenopausal women are ______.

Answer 17

Microadenomas

Microadenomas

Question 18

Mass effect sx in pituitary tumors

Answer 18

Non secretors/weak secretors (non fxning)

1. HA
2. VIsual field deficits
3. Cranial Nerve Palsies
   - Ptosis
   - Diplopia
4. Pituitary Hormone deficits
5. Rare (seizure, stroke, CSF leak)

Question 19

Classic visual deficit in mass effect of pituitary tumors

Answer 19

bilateral temporal hemianopsia

vision is missing in the outer half of both the right and left visual field

Question 20

Most common type of clinically non functioning adenoma (most common adenoma type to come to surgery)

Answer 20

Gonadotroph adenoma

Question 21

Prolactinoma clinical signs/sx

• is it related to OCP?
• Classic Presentation?
• First line tx

Answer 21

1. Amenorrhea
2. Galactorrhea
3. impotence in men

*NOT related to birth control pills

Presentation is often to the OBGYN for premenopausal women

Dont need to use Surgery as first line therapy

Question 22

Cushings disease

Answer 22

ACTH secreting pituitary adenoma

• Central/truncal obesity
• plethora

Question 23

Mutation in Beta catenin can cause which types of cancers?

Answer 23

medullary blastoma

Craniopharyngioma