Pituitary pathology Flashcards
MRI images what three properties of protons in magnetic fields?
1. T1 relaxation rate: tendency of protons to align with magnetic field 2. T2 relaxation rate: loss of magnetization 3. Proton density
most of sellar region masses are
85% pituitary adenomas
- equiv to WHO grade I
- treated by surgical resection
- all (except craniopharyngioma) affect middle age adults
Pituitary adenomas Hyperfunctioning vs Nonfunctioning adenomas
- 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
TTF-1
Thyroid transcription factor
- seen early in gestation in third ventricle
- expressed in posterior gland in adult
Order of appearance of anterior pit. H:
8 weeks
9 weeks
12 weeks
8 weeks
- ACTH, GH
9 weeks
- Alpha subunit
12 weeks
- FSH, LH, TSH
Does size of pituitary adenoma = aggressiveness?
No = WHO grade I
Order of appearance of anterior pit. H:
- ACTH, GH
- Alpha subunit
- FSH, LH, TSH
8 weeks
- ACTH, GH
9 weeks
- Alpha subunit
12 weeks
- FSH, LH, TSH
Which are more common in females?
Microadenomas or macroadenomas?
Microadenomas - females
Macroadenomas - males
Cavernous sinus
contains carotid
- adenomas do not invade blood vessels, but do entrap CN III, IV, VI
Causes of pituitary tumors
95% sporadic
5% familial
4 genes associated with familial pituitary tumor syndromes
MEN1
CDKN1B
PRKAR1A
AIP
do all pts with clinical features of MEN1 have a mutation in MEN1 gene?
No
20% of pts with features of multiple endocrine neoplasia type 1 do not have mutation in MEN1
(maybe CDKN1B)
those have have adenomas that secrete GH may have which mutated gene?
AIP in familial isolated pituitary adenomas
features that suggest an inherited pituitary tumor syndrome:
- parathyroid tumors
- pancreatic endocrine tumors
- atrial myxomas
- lentigines
- Schwann-cell tumors
- Fam hx
- young age at onset
Stain used to see packaging granules in pituitary adenomas
Synaptophysin
- but wont tell you which H are inside the granules
Txn factors for: ACTH GH/TSH PRL FSH/LH
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
85% of usual ACTH adenomas are _____.
Most prolactinomas in premenopausal women are ______.
Microadenomas
Microadenomas
Mass effect sx in pituitary tumors
Non secretors/weak secretors (non fxning)
- HA
- VIsual field deficits
- Cranial Nerve Palsies
- Ptosis
- Diplopia - Pituitary Hormone deficits
- Rare (seizure, stroke, CSF leak)
Classic visual deficit in mass effect of pituitary tumors
bilateral temporal hemianopsia
vision is missing in the outer half of both the right and left visual field
Most common type of clinically non functioning adenoma (most common adenoma type to come to surgery)
Gonadotroph adenoma
Prolactinoma clinical signs/sx
- is it related to OCP?
- Classic Presentation?
- First line tx
- Amenorrhea
- Galactorrhea
- 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
Cushings disease
ACTH secreting pituitary adenoma
- Central/truncal obesity
- plethora
Mutation in Beta catenin can cause which types of cancers?
medullary blastoma
Craniopharyngioma
