Pituitary Pathophysiology Flashcards
Benign tumors of pituitary/hypothalamus
adenomas of AP and tumors of cell rests like craniopharyngiomas and Rathke’s cleft cysts
Infiltrative disease of pituitary
hemochromatosis
Infiltrative disease of hypothalamus
sarcoidosis, Langerhans cell histiocytosis
only _____ can hypersecrete pituitary hormones or fragments thereof
pituitary adenomas
T/F any disease of pituitary or hypothalamus can cause deficiency of any AP hormone
T
T/F any disease of pituitary or hypothalamus can cause a deficiency of vasopressin and thereby cause diabetes insipidus
F –> only a disease of the hypothalamus or infundibulum
Replacement hormone for: GH
Somatropin –> short stature due to gh deficiency/turners/renal failure, GH deficiency in adults
Replacement hormone for: prolactin
none
Replacement hormone for: ACTH
hydrocortisone
Replacement hormone for: TSH
thyroxine
Replacement hormone for: LH/FSH
FSH and hCG
Secretory products of the associated adenoma: somatotroph
GH
Secretory products of the associated adenoma: lactotroph
prolactin
Secretory products of the associated adenoma: corticotroph
acth
Secretory products of the associated adenoma: gonadotroph
FSH (LH rarely)
Secretory products of the associated adenoma: thyrotorph
TSH, alpha subunit
T/F Peptide adenomas are recognizable early in clinical course
T –> somatotroph, lactotroph, corticotroph tend to be efficient in production of secretory products–> make you look “funny” early on
Somatotroph adenomas cause clinical syndromes ____ and ____
gigantism if before epiphyseal closure, acromegaly after epiphyseal closure
Acromegaly
growth of bones after epiphyseal closure –> jaw, nose, frontal bones, hands, feet
Chemical profile of somatotroph adenoma
IGF1 elevation, lack of suppression of GH to an oral glucose load –> histologic apeparance of pituitary adenoma, immunostaining of GH
Consequences of somatotroph adenoma
OA, cancer of colon, CVD, diabetes mellitus, neuropathy/carpal tunnel syndrome, sleep apnea
T/F Acromegaly is associated with higher mortality
T
Tx for somatotroph adenoma
surgical, radiation, pharmacological: dopamine agonist (cabergoline), somatostatin analog (octreotide, lantreotide), GH receptor antagonists (pegvisomant)
GH receptor antagonist
pegvisomant
Dopamine agonist
cabergoline, bromocriptine
Somatostatin analog
octreotide, lantreotide
In premenopausal women, lactotroph adenomas cause ____
amenorrhea/oligomenorrhea, galactorrhea
In postmenopausal women, lactotroph adenomas cause ____
neurologic symptoms
In men, lactotroph adenomas cause ____
hypogonadism: decreased libido, fertility, potency
Physiologic causes of hyperprolactinemia
pregnancy, nursing, exercise, physical/psychological stress
Pathologic causes of hyperprolactinemia
adenoma, dopamine receptor antagonists, catecholamine inhibitors, h2 antagonists, estrogens, opiates
T/F serum prolactin levels >200 are usually adenomas (pregancy up to 400) and <200 are due to other causes
T
Tx of lactotroph adenoma
dopamine agonist
Clinical syndromes of corticotroph adenomas
Cushing’s (common), neurological symptoms (uncommon)
Do thyrotroph adenomas cause hyperthyroidism?
not usually but sometimes
Tx of thyrotroph adenoma mediated hyperthyroidism
somatostatin analog
Gonadotroph adenomas cause _____
neurological symptoms (common) –> visual field impairement, headache ; hormonal abnormality (uncommon) –> premature puberty in boys, ovarian hyperstimulation in premenopausal women
Most common hormonal finding in gonadotroph adenoma
elevated intact FSH, rarely intact LH, elevated subunits of FSH/LH
