Endocrine Flashcards
First test in work-up of suspected acromegaly?
Second test if positive?
First test: IGF-1 level
Follow-up if positive: Oral glucose suppression test for GH (will fail to suppress in acromegaly)
Most common primary pituitary tumor?
Prolactinoma
Kallman syndrome
Hypogonadotropic hypogonadism (pubertal failure) + anosmia
Migration defect in GnRH-secreting and olfactory neurons
Potential cause of rapid-onset hirsuitism +/- virilization in women?
Test?
Androgen-secreting neoplasm
Test: serum testosterone and DHEAS (dehydroeplandrosterone, produced by adrenal neoplasm and converted to testosterone peripherally)
Tumors in MEN1? MEN2A? MEN2B?
MEN1: 3 P’s
- Primary hyperparathyroidism
- Pituitary tumors
- Pancreatic endocrine tumors (esp. gastrinomas)
MEN2A: 2 P’s, 1 M
- Pheochromocytoma
- Primary hyperparathyroidism
- Medullary thyroid cancer
MEN2B: 1 P, 3 M’s
- Pheochromocytoma
- Medullary thyroid cancer
- Mucosal neuroma
- Marfanoid habitus
Pheochromocytoma and thryoid storm can both lead to dangerous hypertension during surgery. What is a key difference?
Thyroid storm will have fever, pheo will not
Most common cause of primary adrenal insufficiency?
Autoimmune adrenalitis
Correction for sodium in hyperglycemia
Add 2 mEq/L Na+ for every 100 mg/dl glucose is above 100
Sign of glucagonoma on exam
Necrolytic migratory erythema: erythematous papules/plaques on face, limbs, and perineum, that enlarge/coalesce over 2 weeks, then develop central clearing and blistering with crust and scale
Cause of “bronze diabetes”
Hereditary hemochromatosis (iron deposition in skin and pancreas, also deposits in liver and other organs)
Major cause of death in hereditary hemochromatosis
Cirrhosis and hepatocellular carcinoma (20x general population)
Oral antihyperglycemics with highest risk of hypoglycemia?
Sulfonylureas (e.g. glipizide, gliclazide, or glimepiride)
Oral antihyperglycemics that can help with weight loss?
GLP-1 agonists (e.g. exenatide)
Oral antihyperglycemics that can lead to heart failure?
Thiazolidenidiones (e.g. pioglitazone)
Treatment for thyroid storm
- Propanolol
- Thionamides (e.g. propylthiouracil, PTU)
- Iodine (blocks thyroid hormone delease, delay 1 hour after PTU)
- Glucocorticoids (decrease T4 -> T3 conversion)
Rare but serious reaction to thionamides (PTU, MMI)
Agranulocytosis
(If patient on these drugs comes in with fever and sore throat, immediately stop drug and get a WBC count to check for agranulocytosis)
Most common form of thyroid cancer?
Pathologic findings on FNA?
Papillary thyroid cancer
Path: Psammoma bodies: grainy, lamellated calcifications
(P for Papillary and Psammoma)
More aggressive but still common thyroid cancer?
Pathologic findings on FNA?
Follicular thyroid cancer (2nd most common, more invasive, can metastasize)
Indistinguishable from follicular adenoma (many follicular cells in clusters and microfollicles).
(Need excisional biopsy of entire nodule to diagnose (invasion in cancer, not in adenoma))
Thyroid cancer that secretes calcitonin?
Medullary thyroid cancer (of parafollicular C cells)
Additional tests needed in patient with medullary thyroid cancer?
Plasma fractionated metanephrine assay for pheo.
MEN2 testing (RET proto-oncogene)
Effect of high titers of anti-TPO antibodies independent of whether patient is euthyroid or hypothyroid?
Increased risk of miscarriage
Diagnostic tests for adrenal insufficiency
A.m. cortisol, ACTH level, ACTH/cosyntropin stimulation test
Normal TSH and T4 but low T3 in a critically ill patient
“Euthyroid sick syndrome” or “low T3 syndrome” - due to decreased conversion of T4 to T3 in a sick patient
Levels of DHEAS, LH, and T in:
Androgen-producing adrenal neoplasms?
Androgen-producing ovarian neoplasms?
Adrenal: elevated DHEAS and T, decreased LH
Ovarian: normal DHEAS, elevated T, decreased LH
