Endocrine ABIM Flashcards
Hypopituitarism causes (3 most common)
Pituitary Tumor, Pituitary surgery, Cranial irradiation
Hypopituitarism: Pituitary Apoplexy: cause, symptoms, treatment
Cause: Pituitary hemorrhage or infarction; Sx: sudden headache, visual change, opthalmoplegia, AMS; Tx: Acute admin of glucocorticoids until adrenal insuffiency r/o; May also require neurosurgical decompression
Hypopituitarism: Postpartum pituitary necrosis (Sheehan syndrome): cause, symptoms
Cause: silent pituitary infarction usually associated with obstetric hemorrhage and hypotension. Sx: Acutely, vascular collapse. More commonly, amenorrhea, inability to lactate, fatigue.
Hypopituitarism: Lymphocytic hypophysitis: what is it?
It causes hypopituitarism, and possibly sx of mass lesion. most cases occur during or after pregnancy.
Hypopituitarism: Signs of pituitary mass effect
Headache & Loss of peripheral vision
Hypopituitarism: Symptoms of anterior hypopituitarism: FSH/LH deficiency - symptoms/testing/findings
FSH/LH: amenorrhea, loss of libido, ED Test: depressed FSH, LH, estradiol or testosterone
Hypopituitarism: Symptoms of anterior hypopituitarism: ACTH deficiency -symptoms/tests/findings
ACTH: fatigue, N/V, Wt loss, Abd pain Tests: Low cortisol/depressed ACTH; depressed response of 11-deoxycortisol and cortisol to metyrapone, positive cortisol response to ACTH
Hypopituitarism: Symptoms of anterior hypopituitarism: TSH deficiency - symptoms/tests/findings
TSH: cold intolerance, weight gain, constipation Tests: depressed free T4 and TSH
Hypopituitarism: Symptoms of anterior hypopituitarism: GH deficiency - symptoms/tests/findings
GH: loss of muscle mass Tests: depressed IGF-1 (serum marker of GH); diminished response to insulin tolerance test ~ insulin induced hypoglycemia
Hypopituitarism: Symptoms of anterior hypopituitarism: DI secondary to ADH deficiency
ADH/DI: polyuria, polydypsia, nocturia Tests: Urine osmo < 200 does not increase with water deprivation test; Positive desmopressin challenge (urine concentrates); MRI or pituitary
Hypopituitarism: Symptoms of anterior hypopituitarism: visual changes
Bitemporal loss of vision (mass effect on optic chiasm)
Hypopituitarism: Symptoms of anterior hypopituitarism: prolactin level
Level may be elevated from loss of tonic inhibition ~ hyperprolactinemia
Hypopituitarism Treatment
Replace hormone deficiency appropriately * Hydrocortisone for adrenal insufficiency
Hypopituitarism Treatment: Central Hypothyroid Tx
Thyroxine dosing based on serum T4 rather than TSH level; T4 replacement only after hypoadrenalism r/o or treated
Pituitary Adenoma: micro vs macro
benign tumors; microadenoma < 10mm; macroadenoma > 10mm
Pituitary Adenoma: 2 ways they become symptomatic
1: mass effect causing hypopituitarism ~ ant pit hormone deficiencies + headaches/visual field disturbances, CN dysfn. 2: endocrine hyperfunction caused by excess secretion by the tumor
Pituitary gland is diffusely enlarged in these 2 situations
Normal Pregnancy & Untreated Primary Hypothyroidism
Pituitary Adenoma: Galactorrhea/Amenorrhea - think this/order this…
Think this: Prolactinoma; Order this: Serum Prolactin Level
Pituitary Adenoma: Enlargement of hands, feet, nose, lips, or tongue; increased spacing between teeth - think this/order this…
Think this: Acromegaly; Order this: Serum IGF-1, OGTT (fails to suppress GH)
Pituitary Adenoma: Proximal muscle weakness, facial rounding, centripetal obesity, purple striae, diabetes mellitus, and hypertension - think this/order this…
Think this: Cushing Disease; Order this: 24-hour urine cortisol excretion, dexamethasone suppression test (suppresses) or late night salivary cortisol level (elevated); serum ACTH level (elevated or inappropriately normal)
Pituitary Adenoma: Goiter & Hyperthyroidism - think this/order this…
Think this: TSH-secreting adenoma (rare); Order this: TSH normal or elevated; increased T4
Pituitary Adenoma: General Testing Rules
- Test all patients w/incidentally discovered pituitary adenoma for hormone hypersecretion 2. Order MRI if testing indicates hormonal hypersecretion from pituitary source 3. If mass effect is presenting sx, obtain MRI first, endocrine testing later (headache/visual) 4. Eval pts with at least 1 component of MEN1 and family hx of MEN1 for a pituitary adenoma (usually hyperparathyroidism)
Pituitary Adenoma: Nonprolactinoma causes of hyperprolactinemia
~ Usually level < 150ng/mL ~ Psychotropic agents, TCAs, Antiseizure meds, Metoclopramide, Domperidone, CCBs, Methyldopa, Opiates, Protease Inhibitors ~ Check TSH level (hypothyroidism can cause it)
Pituitary Adenoma: Tx for women with microprolactinoma/normal menses; Patients with nonfunctioning microadenomas (< 10mm)
Observation
Pituitary Adenoma: Tx for symptomatic prolactinoma
Dopamine Agonist (cabergoline preferred to bromocriptine); consider w/d of RX if prolactin level normalized and mass no longer visible on imaging; Close follow up ~ recurrence rates up to 50%
Pituitary Adenoma: Tx for adenomas secreting GH, ACTH, TSH; Tx for adenomas w/mass effect, visual field disturbance, Tx for hypopituitarism and Tx for prolactinomas unresponsive to dopamine agonist
Surgery
DI: what is it? central vs nephrogenic
Inability to concentrate urine due to insufficient arginine vasopressin (AVP, ADH) release (central) or activity (nephrogenic)
DI: patient history includes…(6 likely scenarios)
- recent head trauma 2. pituitary mass lesion 3. evidence of anterior hypopituitarism 4. h/o infiltrative disorder (such as sarcoidosis) 5. kidney disease (tubulointerstitial disease) 6. meds such as lithium
DI: symptoms/signs of central DI
cravings for water or cold liquids, urinary frequency, nocturia, and, depending on mass effect of pituitary tumor, visual field deficits
DI: initial testing/confirmation testing
Initial: 1. urine osmo < 200 mOsm/kg 2. inability to concentrate urine during water deprivation test Confirmation: 1. desmopressin challenge test (+) urine concentrates = central, order MRI of pituitary; (-) urine does not concentrate = nephrogenic, order u/s kidneys