Endocrinology Flashcards
What is the most common ectopic thyroid?
lingual (tongue)
Which neck mass is anterior and which is lateral?
thyroglossal cyst is anterior (moving with swallowing and tongue movement) and brachial cleft cyst is lateral
Where are follicular and parafollicular cells derived from?
follicular- endoderm
parafollicular-neural crest (secrete calcitonin)
What is the adrenal cortex derived from? what about the adrenal medulla?
cortex=mesoderm (GFR- aldosterone, cortisol, DHEA)
medulla=neural crest (chromaffin cells-catecholamines-epi/NE)
Does glucose or insulin cross the placenta?
glucose does and insulin does not
What happens to GnRH if you get hyperprolactinemia?
decrease it and thus decrease LH and FSH
Note you want pulsatile GnRH for puberty
What is somatostatin used to treat?
acromegaly, decreases GH and TSH
What does calcitonin do?
Decreases the levels of serum calcium (opposite of PTH)
Secreted by parafollicular cells (C cells of thyroid)
What inhibits T4/T3?
PTU (propylthiouracil) and methimazole
What are the functions of T3?
6 B’s brain maturation, bone growth, B-adrenergic, basal metabolic rate, blood sugar, break down lipids
What can cause pathogenic high ACTH? What will cause high cortisol, but low ACTH?
- ACTH secreting pituitary adenoma
- paraneoplastic syndromes (SCLC, bronchoid carcinoids)
High cortisol, low ACTH
- Bilateral adrenal hyperplasia
- Adrenal adenoma
- Adrenal carcinoma
What are the symptoms of adrenal insufficiency?
can’t make enough mineralocorticoids, glucocorticoids to sustain body’s needs so you get fatigue, orthostatic hypotension, weakness, muscle aches, salt and sugar cravings
What increases in primary adrenal insufficiency?
MSH (hyperpigmentation) in response to elevated ACTH
What is Waterhouse-Friderichsen syndrome?
massive adrenal hemorrhage (neisseria meningitidis) causing primary adrenal insuff
what is the difference between secondary adrenal insuff and primary?
with secondary you have low ACTH, so you don’t get hyperpigmentation with elevated MSH and you don’t get hyperkalemia because you still have an intact renin-angiotensin-aldosterone axis
what is teritary adrenal insuff caused by?
exogenous steroids
what are the causes of secondary hyperaldosteronism?
renovascular disease, juxtaglomerular cell tumours (renin producing tumour)
what is the difference between neuroblastoma and wilms tumour?
wilms tumour is smooth and unilateral, neuroblastoma is irregular and can cross the midline. Neuoblastoma looks for HVA and VMA elevated in urine, Get homer-wright rossetes. Neuroblastoma is a tumour of the adrenal medulla. Arises from neural crest cells.
Pheochromocytoma?
most common adrenal medulla tumour in adults- neural crest cells (chromaffin cells)
- rule of 10’s-10% malignant, bilateral, extra adrenal, kids, calcify
- 5 P’s of symptoms,- pressure, pain, palpitations, perspiration, pallor
- give phenoxybezamine
Whats a VIPoma?
secretes vasoactive intestinal peptide- watery diarrhea, hypokalemia, achlorhydria, associated with MEN-1
What antibodies cause Hashimoto’s hypothryoiditis? What kind of cells do you see on pathology?
antithyroid peroxidase and antithyroglobulin antibodies. Hurthle cells on pathology (lymphoid aggregates with germinal centers)
What are the 6 P’s of congenital hypothyroidism?
pot-bellied, pale, protruding umbilicus, protuberant tongue, poo brain development
-caused by maternal antibodies
What is de Quervain thyroiditis?
post viral illness, subacute granulomatous thyroiditis, very tender, usually after viral illness, high ESR, jaw pain
What is Graves disease?
caused by thyroid stimulating immunoglobulins, HLA DR3 and HLA B8, get tall crowded follicular epithelial cells, scalloped colloid
What is a toxic multinodular goiter?
Independent of TSH, releases T3/T4 from hot nodules (rarely malignant), the receptors don’t work. On pathology get hyperfunctioning follicular cells with distended colloid
What are the 4 tx for thyroid storm?
propanolol (beta blocker), prednisone, propylthiouracil and potassium iodide
What are the complications from thyroidectomy?
hoarseness (injury to recurrent and superior laryngeal nerves), hypocalcemia (removing parathyroid glands), dysphagia, dysphonia
What is the most common thyroid cancer and what is the pathology?
papillary-orphan annie eyes (empty nuclear with central clearing), psammoma bodies, inc RET/PTC and BRAF arrangements
Medullary thyroid carcinoma
parafollicular cells- secrete calcitonin, associated with RET mutations, congo red stain, sheets of cells in amyloid stroma
What are the signs of hypoparathyroidism?
tetany, hypocalcemia, hyperphosphatemia. Can cause Chvostek sign (tap facial nerve and get contraction facial muscles) and/or Trousseau’s sign (BP cuff over brachial nerve causes carpal spasm).
McAlbright hereditary osteodystrophy?
Kidney doesn’t respond to PTH, shortened 4th/5th digits, short stature, dev delay, AD but must be given by mother because of imprinting
What is Osteitis fibrosa cystica?
cystic bone spaces filled with fibrous brown tissue (osteoclasts, hemosiderin from hemorrhages) inc PTH (usually from primary which would be parathyroid adenoma or hyperplasia
What is familial hypocalciuric hypercalcemia?
High Ca, but low Ca in urine, G coupled receptors are less responsive to PTH
What is Nelson syndrome?
bigger ACTH pituitary adenoma after removal of adrenal glands for Cushings- get headaches, bitemporal hemianopsia and hyperpigmentation
How do you treat nephrogenic DI?
HCTZ, indomethacin, amiloride, don’t take offending agent, hydration, dietary restriction of salt
What is SIADH- what are the causes?
caused by CNS injury, SCLC, pulmonary diseases, drugs (cyclophosphamide)- tx is water restriction, diuretics, hypertonic saline. Don’t want to correct too fast because of risk of cerebral edema
What is renal path finding of diabetes?
Kimmelstiel-Wilson nodules
What are the testing parameters for diabetes?
fasting >126, oral glucose tolerance >200, HgbA1c >6.5
what are the antibodies that cause T1DM?
glutamic acid decarboxylase antibodies destroy the B cells
What are the symptoms of glucagonoma?
DVT, delirium, declining weight, diabetes, depression, necrolytic migratory dermatitis- tx is surgery and ocetrotide
What are the symptoms and cause of insulinoma?
beta cell tumour- whipple triad-hypoglycemia symptoms, low glucose and resolution of symptoms when you correct glucose-high C peptide- associated with MEN1
Whats a somatostatinoma?
gamma cells- can cause diabetes/glucose intolerance, gallstones, steatorrhea, achlorhydria- decrease secretion of secretin, cholecystokinin, glucagon, insulin- tx with octreotide or surgery
Are MEN syndromes genetically inherited?
AD
MEN 1 3P’s: Pituitary, Parathyroid, Pancreas
MEN 2A 2P’s: Parathyroid and pheochromocytoma
MEN 2B 1P: Pheochromocytoma
How propylthiouracil and methimazole work?
inhibit thyroid perioxidase, inhibit oxidation of iodide, use PTU in 1st trimester then methimazole in 2nd two trimesters
