Pituitary Flashcards
How do exocrine glands secrete substances
via ducts
How do endocrine glands secrete substances
through the cells and rich capillary system
What control the anterior pituitary
hypothalamus
What is the best imaging to see the pituitary gland
MRI
What is the pituitary close to in the brain
- optic chiasm
- cranical nerves III,IV, VI
- trigeminal ganglion
- ophthalmic division V
- carotid artery
- cerebral circulation
What hormones does the anterior pituitary produce
- GH
- prolactin
- ACTH
- TSH
- LH
- FHS
What hormones are stored in the posterior pituitary
- ADH
- oxytocin
What does somatostatin inhibit
growth hormone release
What does dopamine inhibit
prolactin release
What is a pituitary ademona? two types?
benign mass of the pituitary gland
can be functional or nonfunctional
What are the malignant masses of the pituitary gland
- germ cell tumor
- sarcoma
- chordoma
- pituitary carcinoma
What are the cell types of pituitary adenomas
- gonadotroph
- thyrotroph
- corticotroph
- lactrotroph
- somatotroph
- lactrotroph/somatotroph
What is the most common cell type in pituitary adenomas
lactotroph
Which disease/disorder does each pituitary adenoma cell type cause
- gonadotroph: clinically nonfunctioning
- thyrotroph: hyperthyroidism
- lactotroph: hyperprolactenemia
- corticotroph: Cushing’s disease
- somatotroph: acromegaly
What genes may play a role in pituitary adenomas
- MEN1
- GS aplha
- PTTG
- FGF receptor 4
What are the signs and symptoms of pituitary adenomas
- neurologic sx (visual changes, headache, CFS rhinorrhea)
- hormonal abnormlaities
Why do people usually seek medical attention for pituitary adenomas
visual changes (bitemporal hemianopia)
What is pituitary apoplexy
infarct or hemorrhage into the ademona
What are the symptoms of pituitary apoplexy
- severe, acute onset of headache
- vomiting
- visual field defects
- other cranial nerve dysfunction
- fever, neck stiffness
- AMS
What lab do you check for a lactotroph
serum prolactin
What lab do you check for a somatotroph
IGF-1
What labs do you check for corticotroph
24 hr urinary free cortisol and elevated ACTH
What labs do you check for thyrotroph adenoma
- alpha subunit
- T4
- TSH
What labs do you check for gonadotroph
- luteinizing hormone
- follicle stimulating hormone
What do you do if you find an incidentaloma >10mm
typical hormone evaluation
What do you do if you find an incidentaloma <10 mm
- only measure serum prolactin
- MRI at 6 months and 12 months
Treatment goals for nonfunctioning pituitary adenomas
- relief of visual impairment and neurologic sx
- removal of macroadenomas to avoid recurrance
- management of hormonal deficiencies
Treatment for pituitary adenoma
- surgical
- medical
- adjuvant radiation
What postoperative hormone deficiency are present after adenoma removal
- hypocortisolism
- diabetes insipidus or SIADH
Physiological causes of hyperprolactinemia
- sleep
- physical exertion
- food
- stress/trauma
- sex
- pregnancy/post partum
- nursing/nipple stimulation
- surgery
Causes of hyperprolactinemia
- prolactinoma
- acromegaly
- primary hypothyroidism
- seizures
- PCOS
- neurogenic causes
- renal insufficiency
- cirrhosis
What drugs can induce hyperprolactinemia
- ranitidine
- cocaine/amphetamines
- metoclopramide
- opiods
- risperidone
- SSRIs
- verapamil
- hydroxyzine
Are prolactinomas usually macro or micro
MICRO
What is associated with prolactinomas
MEN1
Clinical manifestation of hyperprolactemia
- galactorrhea
- infertility
- osteopenia
- decreased libido
- gynecomastia in men
What do you need for diagnosis of a prolactinoma
- significantly elevated serum prolactin level
- MRI with a pituitary lesions
Labs to order for hyperprolactemia evaluation
- prolactin
- TFTS
- LFTs
- Ca
- Cre/BUN
- HCG
- IGF 1 (mixed adenoma)
When wold you treat a prolactinoma
- tumor growth
- oligo or amenorrhea/ hypogonadism
- bothersome galactorrhea
- infertility
Treatment of prolactinomas
-Dopamine agonist (first choice)
carbergoline- 1st choice
bromocriptine for pregnancy
-surgery
-radiationWhen is surgery indicated for a prolactinoma
- visual field defects unresponsive to medical therapy
- macroadenomas unresponsive to medical therapy
- tumor growth while on medical therapy
- intolerance to medical therapy
- pituitary apoplexy
- CSF rhinorrhea
-
Presentation of acromegaly
- prognathism
- headaches
- vision defects
- skin tags
- ennlarged tongue
- frontal bossing
- coarse features (acral enlargement)
- enlarged hands and feet
- osteoarthritis
- carpal tunnel
What are comorbidities with acromegaly
- HTN/ heart disease
- CVA
- headache
- arthritis
- insulin resistant diabetes
- sleep apnea
Baseline evaluation labs for acromegaly
- IGF 1
- pituitary function test (if macro)
- PRL
- glucose
- LFTs
- Cr/BUN
- MRI
- visual field
Medical treatment for acromegaly
- somatostatin analogs (octerotide, lanreotide)
- dopamine agonists (bromocriptine, cabergoline)
- GH receptor antagonist (pegvisomant)
Where do metastatic pituitary tumors come from
breast cancer in women
lung cancer in men
Where does a pituicytoma arise
posterior pituitary
How does a pituicytoma present
sellar mass, often mistaken for a pituitary adenoma but there is no hormone secretion
Signs and symptoms of germ cell tumors
- headache
- N/V
- lethargy
- diplopia
- hypopituitary
- diabetes insipidus
- Parinaud’s syndrome
What is Parinaud’s syndrome
paralysis of disconjugate gaze seen in germ cell tumors
Where do germ cell tumors arise
third ventricle
Signs and symptoms of chordomas
- headache
- visual impairment
- anterior pituitary hormonal def
Symptoms of metastatic disease to pituitary
- diabetes insipidus
- visual field defects
- anterior pituitary hormonal def
- retroorbital pain and ophthalmoplegia
