Pituitary Pathophysiology Flashcards
What are hormonal consequences of pituitary and hypothalamic diseases?
Hypersecretion: only pituitary adenomas
Hyposecretion: Any disease of pituitary/hypothalamus for anterior pituitary hormones
Hyposecretion of vasopressin can only be caused by disease of hypothalamus or infundibulum
What are signs of GH deficiency? (3)
Short stature prior to epiphyseal closure
Decreased muscle/increased fat mass
Decreased BMD
GH Replacement: What is it approved for and what is its effect
Approved for short stature.
Effects: growth, increase in BMD
Which adenomas involve peptide hormones? What is noticeable effect?
Adenomas involving somatotrophs, lactotrophs, corticotrophs.
Effect: people “look funny”
Which adenomas involve glycoprotein hormones? Are they recognizable?
Ones involving gonadotrophs, thyrotrophs
Only recognizable once they are much larger
Somatotroph Adenomas: Presenation
Acromegaly (huge facial features, big hands) and gigantism
Somatotroph Adenomas: Diagnosis via chemical confirmation (2)
Lack of suppression of Gh in response to oral glucose load
Elevated IGF-1
Somatotroph Adenomas: Dx via pathologic confirmation
Histologic appearance of pituitary adenoma
IHC staining
Consequences of Somatotroph Adenomas (7)
Arthritis (OA), cancer (esp colon cancer), CVD, DM, Neuropathy (carpal tunnel), sleep apnea, death
Somatotroph Adenomas: Pharma Options (3) and other options (2)
Pharmacologic: DA agonists (cabergoline), SS analogs (octreotine), GH receptor antagonists (pegvisomant)
Surgical
Radiation
How does pegvisomant antagonize GH receptor?
Dimerizes GHR
Lactotroph adenomas: Clinical Syndromes
Premenopausal women? (2)
Postmenopausal women? (1)
Men? (3)
Premenopausal: amenorrhea and galactorrhea
Postmenopausal: neurological syndromes
Men: Decreased libido, fertility, potency
Causes of hyperprolactinemia: Physiologic (4) and pathologic (6)
Phys: Pregnancy, nursing, exercise, stress
Path: lactotroph adenomas, DA receptor antagonist, catecholamine inhibitor, H2 antagonists, estrogens, opiates
Treatment of lactotroph adenomas
Dopamine agonists: cabergoline, bromocriptine
Px of Corticotroph Adenomas (2)
Cushing’s syndrome, neurological symptoms
Thyrotroph Adenoma Presentation (2)
(Hyperthyroidism): A-fib and CHF
Thyrotroph Adenoma Treatment and Effect
SS Analogs (octreotide): reduces T4 and TSH…also decreases adenoma size
Gonadotroph Adenomas: Clinical Px (3)
Neurological symptoms: visual field impairment and headaches
Incidental finding on MRI
Hormonal abnormality: Premature puberty in boys, ovarian hyperstimulation
Lab values in Gonadotroph Adenomas:
Elevated FSH, alpha subunit, estradiol
Low LH
What do you see on US in women with gonadotroph adenomas?
Big ol ovaries (due to hyperstimulation)
