Pituitary Flashcards
symptoms of mass effect of pituitary adenomas?
headaches
visual field abnormalities
cranial nerve palsies (rare)
nasal stuffiness (if grow down - rare)
How do you classify microadenomas vs macroadenomas?
micro < 1 cm
macro > 1 cm
invasive adenomas
gonadotropin tumors
non-functioning - asymptomatic and discovered incidentally
Most of them are FSH-producing tumors. Some of them are LH-producing tumors.
Now, this is a sagittal view of the head. You can see this tear-shaped drop thing (X). Just think of this in relationship to the microadenoma that we just saw. This is huge, and this is a macroadenoma. [Note the pituitary stalk (S) for reference.]
Germinoma
most common pituitary/pineal germ cell tumor
hormonal and visual symptoms
cure with biopsy, radiation, chemo
findings in secondary hypothyroidism?
decreased energy
dry skin
constipation
cold inteolerance
aches and pains
Treatment for acromegaly?
surgery is first line - high cure rate (microadenomas)
most tumors are macroadenomas and may not be curable by surgery
debulking still improves response to meds (so do surgery before meds)
give somatostatin or analogs to lower GH (octreotid)
Pegvisomant
Radiation
First line drug for prolactinomas?
cabergoline
used to use bromocriptine
shrinks the tumor a lot!!
serious side effects
meningioma
A usually noncancerous tumor that arises from the membranes surrounding the brain and spinal cord.
- Can see here [arrow] that the Sella turcica is not really increased;
- meningioma is right in the back of it
- and it’s pushing UP
- pt presented with visual problem
-
- What I’m trying to tell you is that visual field is not something that’s pathonomic of one tumor type
- Anything that’s pressing the visual pathway from below will cause visual problem
could be an adenoma, cragiopharyngioma, meningioma, bunch of cysts
secondary adrenal infusfficeincy symptoms
aesthenia, malaise, weakness, weight loss, hyponaturemia
MEDICAL EMERGENCY
treat asap
non-functioning pituitary adenomas
most arise from gonadotropin producing cells (occasionally ACTH)
monoclonal (like other pituitary cells)
most often do not produce high enough levels of gonadotropics because tumors are not efficient hormone producers
bi-temporal anopsia
- My right eye and my left eye have fibers going to each left and right
- The nasal field of my left eye is responsible for seeing the right
- So you check the pt to see whether any of the visual field of the left/right eye is amputated
- What you need to understand is, what happens if you have an adenoma pushing, but growing and compressing the middle portion of the chiasm?
- Bi-temporal anopsia
How do you diagnose secondary hypogonadism?
The diagnosis is low LH, low FSH, low testosterone, or low periods in women. If you have high LH and FSH, it means that the women have premature ovarian failure or menopause. That’s usually what happens. Occasionally with a gonadotropin-secreting tumor you can get that, but it’s usually either menopause where both are elevated or early ovarian failure due to an autoimmune disease which can cause your ovary to fail.
How do you diagnose acromegaly?
an elevated age- and gender-matched IGF-1
You would also give a standardized glucose tolerance test by giving a glucose drink. Glucose suppresses GH. Over a period of 2 hours, one expects GH to be less than 0.4 ng/ml. Usually this is not an issue with people who have obvious acromegaly, but sometimes it can be. So you need to do these two things. Otherwise we generally follow people by measuring the IGF-1, which is grossly elevated. When we lower the IGF-1, the symptoms are improved.
presentation of non functioning adenomas?
The presentation of non-functioning adenomas is often visual abnormalities, headaches
Very frequently there is sexual dysfunction because it has more pituitary insufficiency than any of the other tumors.
There is a prolactin elevation due to pressure of the tumor on the pituitary stalk.
Hypopituitarism includes hypothyroidism, hypoadrenalism, hypogonadism and growth hormone deficiency.
Also pituitary apoplexy, which can cause havoc.
Where is the pituitary located?
- This is where the brain goes to become the spinal cord, and there are a bunch of holes and foramina
- What we have here are 3 “floors” [indicated by numbers]
- The pituitary gland sits right here [circle] in an area called pituitary fossa
- On lateral view, can see Sella turcica [arrow]
Treatment of diabetes insipidus
adequate H2O
DDAVP (form of vassopressin)
MEN-1
syndrome with other neuroendocrine tumors (usually involiving the pancreas)
frequently find prolactinomas
stalk effect
- Sometimes you have a pt that comes in with a relatively elevated level of prolactin, but it’s not that elevated (~150)
- It’s not the level of a true pituitary tumor making prolactin, but it is elevated
Dopamine is coming down from the hypothalamus that normally represses the synthesis and release of prolactin. If you have any pathological process that’s compressing the stalk, preventing the transport of dopamine from the hypothalamus to pituitary gland, you will have stalk effect
-, that inhibitory hormone is no longer able to reach the anterior pituitary, and therefore, the level of prolactin will go up
Mutation in acromegaly
AIP
low penetrance!
optic chiasm
You can certainly see that if the tumor grows up towards the optic chiasm, it may affect vision.
Familial Associated Pituitary Adenomas
FIPA
Acromegaly occurs in families with AIP mutations (autosomal dominant)
clinical acromegaly appears infrequently - low penetrance
side effects of cabergoline?
large-dose cabergoline is associated with cardiac valve abnormalities and fibrosis. We don’t use those kinds of doses in patients with pituitary tumors
signs and symptoms of adult GH deficiency
altered body comp
lipid metabolism
decreased bone mineral densitiy
CV disease
diminished quality and length of life
Rathke’s cleft cyst
- Both (+ craniopharyngeomas) grow from remnants of the Rathke’s cleft pouch
- you can see that this tumor [arrow] does not have minineralization, does not have cystic fluid
- can be operated and pt can be cured
- The problem is, if you don’t discover it, pt comes to medical attn when it’s too late
- Pt alredy has significant visual damage
- So you have really pay attn when a pt complains about visual problem
- Sometimes, you have pts who have migrains, that can be complicated by visual problems, but you have to at least once do an image to see whether there is a tumor or not
causes of diabetes inspidis
tumors
granulmaotous disease
trauma
infection
ischemia
autoimmune
Pegvisomant
drug for acromegaly if Octreotide or others don’t work
. If you change the anatomy of the GH itself, it can bind to only one receptor and prevent dimerization. This blocks GH action in the entire body.
meningioma
How does a non-functional pituitary adenoma present?
visual disturbances
gets really big and crushes optic nerve
meningioms
where is the pineal gland?
1
- Pineal gland [1]
- Superior colliculi [2]
- Inferior colliculi [3]
- Cerebral aqueduct [4]
- This is what allows the communication b/w the 3rd ventricle and the 4th ventricle
- Cerebellum [6]
- Pons [7]
- Midbrain [5]
glial cysts of the pineal
immunostaining of pituitary adenomas
- We have a battery of immunostain in the lab, including LH, FSH, TSH , prolactin, ACTH
- We do this on patients that have the surgery to see whether or not there is immunoreactivity
- It’s not b/c there’s immunoreactivity in the cell that tells us the adenoma is functional
- You may have protein IN the cell, but may not be released from the cell
- ie. May not be released in blood, so will not be functional, but still be able to detect by immunochemistry
What are the posterior pituitary hormones?
ADH
Oxytocin
Sheehan’s syndrome
post-partem complication
type of pituitary apoplexy but non-adenomatous
- Woman just delivered her baby, and very quickly, becomes HYPOpituitary
- During pregnancy, anterior pituitary is increasing in size and vasculature (hyperplasia)
- w/ increase in size, there is increase in blood flow
- during the delivery, pt is losing a lot of blood
- one of the most common cause of Sheehan’s syndrome is tremendous blood loss (big risk factor)
- an organ like the anterior pituitary that is relying on a high blood flow
- if you lose a lot of blood, pituitary is going to pay the price of hypovolemia first
- Sheehan’s syndrome = apoplexy of non-adenomatous pituitary gland, very often in pregnant post-partem women
pineocytoma
neoplasm of the pineal gland
- Tumor cells are round, monomorphic, not aggressive
- sometimes they can disseminate, although they’re not high grade tumor
- that can create problems
what are anterior pituitary hormones?
TSH –> thyroid
ACTH –> adrenal cortex
GH –> bone etc.
FSH/LH –> testis ovaries
Prolactin –> mammary glands
sella turcica
sella turcica (Latin for Turkish seat) is a saddle-shaped depression in the body of the sphenoid bone of the human skull. The seat of the saddle, the deepest part of the sella turcica known as the hypophyseal fossa, holds the pituitary gland (hypophysis).
cranioharyngioma
Craniopharyngioma is a type of brain tumor derived from pituitary gland embryonic tissue, that occurs most commonly in children
adamantinomatous, squamous papillary
local recurrence 25%
mineralization and bone formation
When they become invasive adenoma, they might look like this. You’re really not seeing any of the normal structures in the hypothalamus. All you’re seeing are the carotid arteries that look open. When the tumor goes around one of the carotid arteries (X), that’s a diagnostic invasiveness. The radiologists use that to determine whether it is definitely invasive.
There could also be micro-invasion. If there’s even a microadenoma next to the cap of the sinus [see next slide], it can really still be invasive. You can get these in all different flavors.
glial cysts of the pineal
cystic disease
where is the hypothalamus?
- The hypothalamus on both sides of the 3rd ventricle is just ABOVE the stalk
craniopharyngeoma
This is a picture of a craniopharyngioma. You can see the calcification in the area of the pituitary (circle). Particularly in children, caraniopharyngiomas are calcified. This is one thing to alert you to the probability that something is a craniopharyngioma.
rathke’s cleft cyst
- Both of them grow from remnants of the Rathke’s cleft pouch
- you can see that this tumor [arrow] does not have minineralization, does not have cystic fluid
- can be operated and pt can be cured
- The problem is, if you don’t discover it, pt comes to medical attn when it’s too late
- Pt alredy has significant visual damage
- So you have really pay attn when a pt complains about visual problem
- Sometimes, you have pts who have migrains, that can be complicated by visual problems, but you have to at least once do an image to see whether there is a tumor or not
splenoid sinus
If it grows down into the splenoid sinus, it may affect nasal [function and manifest as] stuffiness or a leakage of CSF, which is clear and has a little sweet flavor.
This is a picture of a microadenoma. This is a normal pituitary gland (P) with a carotid artery (A) on either side, and you can see this greyish area over here (X). The characteristic of microadenomas is that they don’t pick up dye during an MRI. This helps make the diagnosis.
prolactinomas symptoms and mechanism
The most common
galactorrhea - non nursing production of milk from lacile glands
ammenorrhea
decreased libido and erectile dysfunction
osteoporosis
Most hormones are controlled by an increase in action because of a stimulating hormone, whereas prolactin is really controlled in a negative way. You probably heard of this before in your lectures, so we’ll just go over it again today. If you interrupt the stalk and the flow of dopamine, rather than having a decrease in dopamine you’re going to have an increase in dopamine because dopamine is really inhibiting the release of prolactin into the circulation. Many people with pituitary tumors have a slightly elevated prolactin due to this interruption in the dopamine control.
craniopharyngeoma
- This reminds me to tell you that this brown structure (in the middle) is so classic for this tumor
- This is what ppl call “crank engine oil”
- When a surgeon drains this cysts, looks very viscous, very oily, brown, dark
- You don’t need a pathologist – when the surgeon drains this cysts, they know it’s a craniopharyngioma
- There isn’t another tumor that can do that
This tumor had cystic component [brown] and solid component [white]
