Endocrine Pathology Flashcards
How can metyrapone be used to determine adrenal insufficiency?
Metyrapone blocks the last step of steroid synthesis.
Normally steroids would decrease and ACTH would increase.
With adrenal insufficency ACTH remains decreased after the test.
Primary adrenal insufficiency
Deficiency of aldosterone and cortisol production due to loss of gland function.
What is addison disease?
Adrenal atrophy or destruction by disease
Look for ACTH skin pigmentation.
What is waterhouse-friderichsen syndrome?
Acute primary adrenal insufficiency due to adrenal hemorrhage associated with septicemia.
What is secondary adrenal insufficiency?
Decreased pituitary ACTH production
There will be no skin hyperpigmentation and no hyperkalemia (aldosterone synthesis is preserved)
Just know the secondary form spares the skin/mucosa.
What is tertiary adrenal insufficieny?
Seen in patients with chronic exogenous steroid use. Percipitated after an abrupt withdrawl.
Aldosterone synthesis is unaffected.
Neuroblastoma
Most common tumor of the adrenal medulla in children usually less than 4 years old.
Look for homer wright rosettes
Dancing eyes and dancing feet with distended abdomen in a child. Upon visualization there are many Homer wright rosettes.
This is characteristic of Neuroblastoma.
Homovanillic acid and vanillylmandelic acid seen in urine
Sign of neuroblastoma
A tumor of the renal medulla.
What gene is overexpressed with neuroblastoma?
N-myc
Pheochromocytoma
Most common adrenal medulla in adults derived from chromafin cells.
Look for secretion of NE, D, and Epi
This tumor is associated with Hippel-Lindau disease, MEN 2A and 2B
Pheochromocytoma
How would one treat pheochromocytoma?
Excessive NE and epi release. Use phenoxybenzamine (alpha 1 and 2 blocker) first.
then use Beta blockers to make sure theres no hypertensive crisis that occurs.
How would hypothyroidism affect cholesterol levels
Hypercholesterolmia
Due to decreased LDL receptor expression.
How would hyperthyroidism affect cholestrol levels?
Hypocholesterolemia.
Most common type of hypothyroidism in areas where iodine is in abundance?
Hashimotos thyroiditis
What occurs in hashimotos thyroidits?
Autoimmune disorder against peroxidase, antimicrosomal, and antiyhroglobulin antibodies.
Thus iodine is not being organified and the globulins that carry the hormones are destroyed.
Which hypothyroid disorder is correlated with Hurthle cells and an enlarged non tender thyroid?
Hashimoto thyroiditis.
Cretinisim
Congenital hypothyroidism
Typically from maternal side.
Look for pot bellied, pale, puffy faced child, protuberant tongue and poor brain development.
Subacute thyroiditis
Self limited disease with flu-like illnesses. Causes hypothyroidism.
Very tender thyroid, increased sed rate (inflammation)
Reidel thyroiditis
Thyroid completely replaced by fibrous tissue (Think Reidel helmet). Causes hypothyroidism.
Fixed, rock hard painless goiter.
What is the most common cause of hyperthyoridism?
Graves disease.
Autoantibodies IgG against TSH receptors on the thyorid!
retro-orbital fibroblasts cause exopthalmos.
Toxic multinodular goiter
Look for focal patches of hyperfunctioning follicular cells working independently of TSH due to mutation in TSH receptor.
Increases release of T3 and T4.
What is a thyroid storm?
Stress induced catecholamine surge seen as a serious complication of thyrotoxicosis!
Increased ALP due to bone turnover
What do you treat thyroid storm with?
3 Ps
Propanolol
Propylthiouracil (Pth antithyroid drug)
Prednisolone
What is Jod-Bosedow phenomenon?
Thyrotoxicosis and hyperthyroidism in ptients with iodine deficiency.
What is the most common form of thyroid cancer and how does it resent?
Papillary carcinoma.
Presents with empty appearing nuclei with central clearing “Orphan annie eyes”
Psammoma bodies and nuclear grooves.
Thyroid cancer related to psammoma bodies and orphan annie eyes
papillary carcinoma
Thyroid cancer related to RET and BRAF mutations
Papillary carcinoma
Which type of thyroid cancer will cause calcitonin and sheets of amyloid depositon?
Medullary carcinoma
Originates from C cells.
what type of thyroid cancer is related to hashimoto thyroiditis?
Lymphoma
What is the sign called when you tap on someone face and the facial muscles spasm?
Chvostek sign seen in hypoparathyroidism
Think “Cheek”
What is the sign called when you occlude the brachial artery and it results in a carpal spasm?
Trousseau sign!
What is familial hypocalciuric hypercalcemia?
This is a familial issue where there is a defective calcium sensing receptor on parathyroid cells.
PTH cannot be suppressed by an increase in calcium level. Thus the patient will have a mild hypercalcemia with normal to slightly increased PTH levels.
Stones, Bones, Groans, and psychiatric overtones
This is osteitis fibrosa cystica caused by hyperparathyroidism. Seen only in primary hyperparathyroidism.
Leads to cystic bone spaces filled with brown fibrous tissue. “Brown tumors”
Secondary hyperparathyroidisms
Secondary hyperplasia due to decreased calcium absorption and or increased phosphate levels.
Most often in chronic renal disease (hypo vitamin D leading to decreased calcium absorption)
Hypocalcemia and hyperphosphatemia with chronic renal failure.
Tertiary parahyperthyroidism
Refractory hyperparathyroidism resulting from chronic renal disease.
Greatly increased PTH and calcium levels.
What is most commonly seen in pituitary adenomas?
Prolactinoma!
Treat with bromocriptine or cabergoline
Pegvisomant
This is a growth hormone receptor antagonist used to treat acromegaly.
Octreotide
Somatostatin analogue used to treat acromegaly.
Stops GH release.
Central diabetes insipidus
Decreased ADH levels*** from the brain
Urine specific gravity < 1.006
Nephrogenic Diabetes insipidus
Hereditary secondary to kidney damage destroying ADH receptors!
Think hypercalcemia, lithium, and demeclocycline (ADH antagonist) damaging the kidney.
Urine specific gravity <1.006
ADH levels will be normal.
Treat with indomethacin, amiloride (increases lithium secretion), and hydration.
How will urine osmolarity compare to serum osmolarity when there is SIADH?
Urine osmolarity will be much higher than serum (absorb all water and urinate out all sodium)
The body responds by lowering aldosterone and dumping out salt. This can cause cerebral edema.
What is a huge problem related to excessively low serum sodium levels?
If sodium levels dip too low, from compensation to excess ADH levels there is a risk for cerebellar edema and seizures.
Sheehan syndrome
Ischemic infarct of pituitary followign post partum bleeding
You’ll see a lack of lactation, absent menstation and cold intolerance!
Whipple triad
Seen in insulinoma Overproduction of insulin leading to... Low blood glucose Symtpoms of hypoglycemia And resolution of symptoms after regularizing glucose.
Elevated blood levels in insulinoma
Increased C-peptide and low blood sugar.
tumor in the bowel secreting serotonin leading to excessive diarrhea cutaneous flishing, and asthmatic wheezing
Carcinoid syndrome
Gastrin secreting tumor of the pancrease or duodenum leading to excssive acid secretion
Zollinger-Ellison Syndrome
Most common with MEN 1
How can you test for gastrin secreting tumors?
Secretin stimulation test.
If you administer secretin and gastrin levels remain elevated (normally inhibits).
What is the inheritance of all the MEN syndromes?
Dominant
All men are dominant
MEN 1
PArathyroid tumors
Pituitary Tumors
Pancreatic endocrine tumors - Zollingers
“Three P’s”
MEN 2A
Parathyroid hyperplasia
Pheochromocytoma
“Two P’s”
MEN 2B
Pheochromocytoma
“1 P”
