Endocrine Part 5 Flashcards
What are 2 diagnostic clues for Conn’s syndrome?
unexplained hypokalemia and hypernatremia
Usually due to the presence of a functional adrenal adenoma or adrenal hyperplasia
Conn’s syndrome
What condition is synonymous with adrenal hyperfunction?
Cushing’s syndrome
What is Cushing’s syndrome most commonly due to?
long term use of pharmacologic doses of gluccocorticoids
Drugs such as prednisone suppress what 2 things?
ACTH and CRH
If Cushing’s syndrome is not due to pharmaceuticals, what is it due to?
tumors (adrenal or pit– particularly tumors involving the corticotroph cell line)
Prolonged excess ACTH will eventually result in what?
adrenal hyperplasia
Adenomas within the … can result in … which can lead to….
zona fasiculata; excess cortisol; primary Cushing’s syndrome
Non-pit and non-adrenal tumors can also result in Cushing’s syndrome as a result of what?
ectopic ACTH
Most common tumor associated with the para-neoplastic production of ACTH
carcinoma of the lung
80% of Cushing’s syndrome tumors are ACTH dependent. What are 2 tumors leading to this?
Pituitary tumors, lung cancer and other tumors
20% of Cushing’s syndrome tumors are independent of ACTH. What are 2 examples?
Benign adrenal tumors/adenomas, malignant adrenal tumors i.e. adrenal cell carcinoma
Condition of adrenocortical insufficiency
Addison’s disease
What is characteristic of primary Addison’s disease?
Adrenal gland itself is damaged
What is characteristic of secondary Addison’s disease?
insufficient ACTH results in atrophy of adrenal cortex
What is the most common cause of primary Addison’s disease?
autoimmune destruction of the adrenal cortex
What are 3 other autoimmune conditions associated with primary Addison’s disease?
Type 1 DM, Hashimoto’s thyroiditis, Vitiligo
What is due to markedly increased levels of ACTH?
hyperpigmentation
due to inadequate secretion of ACTH by the anterior pituitary
secondary Addison’s disease
Adrenal function loss due to trauma or adrenal hemorrhage from sepsis
Waterhouse-Frederickson syndrome
Patients with secondary Addison’s disease have diminished levels of … thus, no stimulation of melanocyte production of melanin
ACTH
W-F syndrome is usually caused by what?
severe bacterial infection
What is the most common bug leading to W-F syndrome?
n. meningitidis
inborn error of metabolism with a specific deficiency of one or more of the enzymes involved in cortisol synthesis
congenital adrenal hyperplasia (CAH)
What deficiency accounts for 95% of CAH cases?
21-Hydroxylase deficiency
Results in the blockage of cortisol production and causes a subsequent increase in ACTH levels
21-Hydroxylase deficiency
What 2 things are increased with 21-hydroxylase deficiency?
17-Hydroxyprogesterone and androstenedione
Blockage of cortisol in 21-hydroxylase results in…
increased shunting to cortisol precursors
ACTH is (high/low) with 21-Hydroxylase deficiency
high
Most significant pathological condition associated with the adrenal medulla
pheochromocytoma
catecholamine secreting tumor of the chromaffin cells within the adrenal medulla
pheochromocytoma
hallmark symptom of pheochromocytoma
hypertension that may be variable and very labile
Think of what in a patient with pheochromocytoma?
MEN IIa or IIb
Associated with the presence of a pheochromocytoma, medullary carcinoma of the thyroid, and/or hyperparathyroidism
MEN IIa
associated with the presence of a pheochromocytoma, muscosal neuromas, and/or hyperparathyroidism
MEN IIb
Biochemically and clinically asymptomatic adrenal masses found incidentally as a result of unrelated imaging
Incidentalomas
What percentage of all adrenal tumors are found to be malignant?
1%
What are 3 examples of primary adrenal cancer?
neuroblastomas, adrenocortical carcinomas, minority of adrenal pheochromocytomas
Essentially a carcinoma of the nervous system and may be seen anywhere along the sympathetic chain
neuroblastomas
Neuroblastomas originate from what cells?
neural crest cells
Accounts for approx 10% of all childhood cancers in the US
Neuroblastomas
Most common solid, extra-cranial malignancy in infants and children
neuroblastoma
What percentage of neuroblastomas occur during the first 8 years of life
90%
What percentage of neuroblastomas occur during the first 2 years of life
50%
