What is the BEST imaging modality for the pituitary?
MRI (T1)
Definition of HYPOpituitarism
Diminished or absent secretion of 1 or more pituitary hormones
7 I’s (causes) of HYPOpituitarism
- Invasive
- Infarction
- Infiltrative
- Injury
- Immunologic
- Iatrogenic
- Isolated
What are the 2 diseases associated w/Infarction that leads to HYPOpituitarism?
- Sheehan’s Syndrome (MC)
2. Apoplexy
Invasive: Why are large pituitary adenomas more likely to cause hypofunction in the pituitary than small ones?
Large pituitary adenomas cause compression of surrounding structures –> meningiomas, lymphoma, metastatic CA, etc
Definition of Sheehan’s Syn?
Bleeding into the pituitary
Who is most likely to develop Sheehan’s syndrome
pregnant women in the postpartum period
Why do lactotroph cells die in Sheehan’s syndrome? result?
lactotroph cells have an increased demand for blood but hemorrhage decreases the blood supply –> ischemia & necrosis
3 Signs/Sxs of Sheenhan’s Syndrome
Who is likely to have Sxs in Sheehan’s
- Agalatorrhea (decr breastmilk production) –> dont lactate
- post-partum menstrual irregularities
- Fatigue
Usu Sheehan’s is only symptomatic in breastfeeding women
What are the 3 diseases associated w/Infiltration that leads to HYPOpituitarism?
- Sarcoidosis
- Hemochromatosis
- Langerhan’s Histicytosis
What types of Injuries can cause HYPOpituatrism?
head trauma, physical abuse (subdural hematomas)
What dz is associated w/Immunologic that leads to HYPOpituitarism?
Lymphocytic Hypohysitis
- Autoimmune d/o –> destruction of AP
What 3 things associated w/Iatrogenic that leads to HYPOpituitarism?
- Surgery &
- Radiation therapy
- infections
What is the progression of hormone defic seen in HYPOpituitarism from early to late?
GH FSH, LH TSH ACTH PRL
“Good Fucking Losers TAP out”
If the pituitary is failing –> HYPOpituitarism what do you expect the levels of pituitary hormones to be
pituitary secreting hormones will be LOW
AP failure –> cant release its hormones
- LOW TSH, LH, FSH, ACTH
If a gland is failing (ovaries) –> HYPOpituitarism what do you expect the levels of pituitary hormones to be
pituitary secreting hormones will be HIGH
ovaries fail –> less neg feedback on hypothalamus –> more AP stimulation –> HIGH LH, FSH, etc
Dx test for HYPOpituitary function?
When is this test not done
What diseases/ disorders is it used to Dx?
ACTH Stimulation Test
NOT done in eval thyroid or gonadotropin failure (ovaries)
Used to Dx Adrenal Insufficiency & GH Defic
How is the ACTH stimulation test done? (what is given and what do you measure/when)
Give ACTH (Cosyntropin) –> measure cortisol levels 30-60 min later
In PRIMARY Adrenal Insufficiency (adrenal gland failure) what do you expect the Cortisol, Aldosterone, ACTH baseline levels to be?
Cortisol & Aldost is low b/c adrenals failing and cant releases them –> less negative feedback on Hypothal –> upreg CRH –> incr ACTH
Baseline ACTH is HIGH
In PRIMARY CENTRAL Adrenal Insufficiency (pituitary or hypothal failure) what do you expect the Cortisol, Aldosterone, ACTH baseline levels to be?
Hypothal/pituit fails –> lows levels of ACTH at baseline
but when give ACTH –> adrenals to rel cortisol and aldost
Cortisol & aldost = normal
(General) Tx for HYPOpituitarism?
Hormone replacement
- give them whatever they are defic in
Tx for HYPOpituitarism if:
- ACTH defic
- TSH defic
- Gonadotropin defic
- GH defic
- ACTH defic –> Glucocorticoids (Hydrocortisone, Prednisone)
- TSH defic –> Levo
- Gonadotropin defic –> estrogen, progesterone, testosterone
- GH defic –> GH
If you suspect Adrenal Insufficiency AND hypopituitarism why must you give glucocorticoids before Levothyroixine?
Opposite order (Levo then glucocorticoids) –> adrenal crisis
(T4 –> less negative feedback on hypothalamus –> more CRH –> more aCTH –> more cortisol)
How is GH defic PRIMARILY diagnosed?
Other test helpful in Dx?
Clinically - using height/wt chart comparisons
GH stim test can be helpful for Dx
What kids require eval for GH defic? (3 situations)
- Kids w/short stature < 2.5 SD below mean
- Height velocity < 25th percentile
- evid of hypothalamic-pituitary dysfunction
3 things assoc w/COMPLETE GHDefic?
- Growth failure
- Delayed bone age
- VERY LOW hormone levels (GH, IGF-1, IGFBP-3)
Tx for GH defic?
GH
Are most pituitary adenomas benign or malignant?
Micro or macro?
Most are benign and MICROadenomas
What does functional vs non-functional adenoma means?
functional - adenoma hypersecretes hormone(s)
non-functional - adenoma does NOT secrete hormones
If an adenoma is compressive what mass effect sxs can it cause?
- HA
- optic chiasm mass effect –> bitempotemporal hemianopsia
what is bitemporal hemianposia
tunnel vision –> cant see out on periphery
What is the MC cell type for pituitary adenomas? what does it secrete?
MC = lactotrophs –> secrete PRL
Definition of prolactinoma
BENIGN tumor of the lactotroph cells –> hypersecretes PRL
Define size difference b/t MACRO vs MICROadenoma
note: higher levels of PRL –> larger tumor
MACROadenoma is > 10mm or 1 cm
MICROadenoma is < 10mm or 1 cm
Sxs of prolactinoma in women?
Men?
F: Galactorrhea, amenorrhea, menstrual irreg
Men: ED/impotence, gynecomastia
Both: decr libido, infertility
What inhibits PRL secretion?
DA
What type of medication is used to Tx prolactinomas (OR ANY OTHER PITUITARY ADENOMA)? specific names of 2 drugs?
DA agonists
- Bromocriptine
- Cabergoline
Name of surgery for Prolactinomas (of any type)?
Transsphenoidal surg
Criteria to perform gamma-knife radiation therapy on prolactinoma?
Tumor must be at least 5 mm from optic chiasm
Other than PRFs what is the other stimulatory factor for PRL rel?
TRH!!
How does hypothyroidism lead to hyperprolactinemia
Hypothyroidism –> low T3/T4 –> less neg feedback on hypothal –> more TRH rel –> more PRL rel
TRH & PRFs are stimulators for PRL
What is a somatotropinoma
GH secreting pituitary adenoma
How does acromegaly differ from gigantism in regards to linear bone growth?
Acromegaly - NO linear bone growth (epiphyseal plates already fused in adulthood)
Gigantism - YES linear bone growth
What does GH stimulate in the liver than leads to most manif of acromegaly?
GH stimulates IGF-1 in the liver
Screening test for acromegaly? Result?
IGF-1 - will be increased
Dx test for acromegaly? Results?
GLUCOSE suppression/tolerance test
GH excess (acromegaly) –> incr Glucose DOES NOT suppress GH
Med tx for acromegaly specifically? 2 drug names?
somatostatin analogs –> inhibit GH secretion
- Octreotide, Lanreotide
After TSS (transsphenoidal surg) which hormone levels normalize w/in hours, which takes longer?
GH normalizes 1st –> IGF-1 takes longer
3 F/u for somatotropinoma/acromegaly?
MRI yearly
colonoscopy Q3-4 yrs (risk of polyps/CA)
CV eval
What is an adrenocorticotropinoma?
What dz can it cause?
pituitary tumor secreting ACTH
that can cause Cushing’s Dz
Difference b/t Cushing’s Dz and Syndrome
Cushing’s Dz –> caused by incr in ACTH from pituitary
Cushing’s Syn –> inc cortisol (less specific cause)
5 Dx tests for Cushings
- 24 hr urinary cortisol
- Late nigh salivary cortisol
- Dexamethasone suppression test
- Basal ACTH level
- Central venous sampling
What result do you expect for Cushing’s Dz when Dexamethasone suppression test given?
Give Dexamethasone –> suppression of ACTH = Cushing’s Dz
If ectopic ACTH tumor it wont supress
What result do you expect for Cushing’s Dz when ACTH basal level tested?
ACTH level will be normal/increased
- b/c tumor secreting ACTH
What result do you expect for Cushing’s Dz when ACTH basal level tested?
ACTH level will be normal/increased
- b/c tumor secreting ACTH
Do gonadotropin adenomas secrete more LH or FSH?
2 syndromes/manif seen?
What subunit elevated (dx)
Only Tx?
FSH >LH
HYPO: pituitarism, gonadism
alpha subunit elevated
SURGERY ONLY (no meds)
Presentation of TSH secreting adenomas? what is not present?
HYPERthyroidism w/goiter BUT NO exophtalmopathy
Dx of TSH secreting adenoma:
- what hormones elevated?
- alpha subunit: TSH ratio?
- hormones elevated –> TSH, TH (T3/4)
- alpha subunit: TSH ratio is > 1
Cause of apoplexy?
hemorrhagic necrosis of tumor or pituitary gland infaraction
Sudden onset of frontal HA Visual acuity/field loss Opthalamoplegia Meningismus N/V, Fever, AMS, HotN
signs of Apoplexy
1st line Tx for apoplexy?
Why is surgery done?
IV dexamethasone –> decr cerebral edema
surgery –> prev permanent vision loss
3 P’s of MEN1
Inheritance pattern?
Pituitary adenomas
Parathyroid adenomas
Pancreatic tumors
MEN = Auto dominant
How is the sella turnica affected in empty sell syndrome? what is the result on the pituitary?
Sella turnica enlarges and fills w/CSF –> compresses/flattens the pituitary
who is Empty Sella Syndrome MC in and what Sx do they have?
Note: Dx = MRI, No Tx
Middle aged obese women w/HTN
What 2 major d/o occur in the Posterior Pituitary
Central Diabetes Insipidus
SIADH
Difference b/t DI and SIADH
DI = defic of ADH SIADH = excess ADH
Why excrete lot of dilute urine in DI?
decr ADH –> less H2O reabsorbed –> more urine excreted
4 main Sxs of DI
- Polyuria –>
- Polydipsia
- Dehydration
- HoTN
when do pts become clinically symptomatic w/ DI?
When they have decreased oral free water intake
Labs in DI?
Hypernatremia, high serum osm, low urine osm
Dx test for DI (in general)? How to do it? results expected in DI?
Water/fluid deprivation Test
deprive pt of water –> continued production of dilute urine in DI
Dx for determine whether Central or Nephrogenic DI?
Results expected for Central?
ADH stimulation test
give ADH –> reduce urine output & incr urine osm
Tx for Central DI?
DDVAP (synthetic ADH –> hormone replacement)
fluids
Labs/volume status seen w/SIADH
HYPOnatremia, decr serum osm, incr urine osm (opposite of DI)
Pts are EUVOLEMIC!
When do pts become clinically symptomatic w/SIADH
SIADH - symptomatic when increase oral free water intake
Tx options (3)..mainstay?
- Tx underlying d/o
- Fluid restriction = mainstay
- ADH/AVP antagonists
- promotes water excretion