Pituitary adenoma Flashcards
Pituitary adenoma characteristics
Most commonly prolactinoma
Finding: amenorrhea, galactorrhea, low libido, infertility (low GnRH)
Can impinge on optic chiasm; bitemporal hemianopsia
Tx: dopamine agonist (bromocriptine or cabergolin) to shrink the tumor
Acromegaly:
cause
Excess GH in adults,
typically caused by pit adenoma
Acromegaly:
characteristics
Large tongue with deep furrows, Deep voice, Large hand and feet Coarse facial features Impaired glucose tolerance (insulin resistance)
Acromegaly:
diagnosis
high serum IGF-1
Failure to suppress serum GH by oral glucose tolerance test.
Pituitary mass seen on brain MRI
Acromegaly
treatment
Pituitary adenoma resection followed by
somatostatin analog if not cured
Diabetic insipidus:
characteristic
Intense thirst and polyuria together
inability to concentrate urine due to lack of ADH
or renal response
Diabetic insipidus:
Causes
Central: pit tumor, trauma, surg, histiocytosis X
Renal: hereditary or 2nd to hypercalcemia, lithium, democlocycline (ADH antagonist)
Diabetic insipidus:
Finding
Urine specific gravity < 1.006
Serum osmolality >290 mOsm/L
Diabetic insipidus:
Diagnosis
Water deprivation test;
urine osmolality does increse
Response to desmopressin distinguishes central DI from nephrogenic DI
Diabetic insipidus:
Treatment
adequtate fluid intake
Central DI: intransal desmopressin (ADH analog)
Nephrogenic DI: hydroxhlorothiazide, indomethacin, amiloride.
SIADH
presentation
1) Excessive H20 retention
2) Hyponatremia with continued urinary Na+ excretion
3) Urine osmolarity > serum osmolarity
4) Body responds with reduced aldo (hyponatremia) to maintain near-normal volume status
5) Very low serum Na+ can lead to seizure (correct slowly)``
SIADH
causes
1) ectopic ADH (small lung cell tumor)
2) CNS disorder/head trauma
3) pulm disease
4) drugs (cyclophosphamide)
SIADH
treatment
Fluid restriction IV saline Conivaptan Tolvaptan Demeclocycline
