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.