179b/180b/183b - Adrenal Pathology, Adrenal Medulla, Adrenal Cortex Flashcards
What 3 things regulate aldosterone secretion?
- RAAS
- Hyperkalemia
- ACTH
ACTH stimulates desmolase, the 1st step in aldosterone synth; however, not a primary regulater of aldosterone synthesis
Where do parasympathetic paragangliomas usually arise?
Parasympathetic nerves in the head, neck, and upper mediastinum
“Head and Neck paragangliomas”
Which pharmacologic agent can be used to block glucocorticoid receptors?
Mifepristone
(progesterone receptor/glucocorticoid receptor antagonist)
11-beta-hydroxylase is required to synthesize aldosterone
Why don’t people with 11-beta-hydroxylase deficiency have low blood pressure?
Deoxycorticosterone can activate aldosterone receptors, leading to water and Na+ reabsorption -> hypertension
Deoxycorticosterone is the substrate of 11-beta-hydroxylase in aldosterone synthesis
Which enzyme converts norepinephrine to Epinephrine?
Where is this enzyme found?
Phenylethanolamine N-methyl transferase
ONLY in the adrenal medulla
=> no other organ can secrete epinephrine
Which tumors most commonly metastasize to the adrenal gland? (2)
Renal cancer
Lung cancer
Which genetic syndromes are associated with pheochromocytoma? (3)
- MEN 2
- Von Hippel-Lindau
- NFM-1
A. Zona Fasiculata
- Mifepristone is also a glucocorticoid receptor antagonist
- Cortisol is produced in the zona fasiculata
What tumors are associated with Von Hippel Lindau? (6)
- CNS Hemangioblastoma
- Pancreatic cyts
- Pheochromocytomas
- Retinal angioma
- Renal cysts
- Renal cell carcinomas
The Hippo might need CPPRRR
What tumors are common to MEN-2A and MEN-2B?
How can they be differentiated?
-
Both = medullary tumors
- Medullary thyroid carcinoma
- Pheochromocytoma
- Caused by activating mutation in the RET proto-oncogene
-
MEN-2A
- Parathyroid hyperplasia
- Less severe than MEN-2B
-
MEN-2B
- Marfanoid appearance (Thin face, big lips, tongue nodules)
- Mucosal neuroma
What is the effect on insulin and glucagon secretion of:
- alpha-adrenergic receptor activation:
- beta-adrenergic receptor activation:
- alpha-adrenergic receptor activation: Inhibits secretion
- beta-adrenergic receptor activation: Stimulates secretion
What is the most common adrenal tumor?
Adrenal cortial adenoma
(Benign)
Describe the gross and histological findings of an adrenal cortical adenoma
Like the normal adrenal gland
- Gross: Yellow-ish
- Histological No necrosis, hemorrhage, or mitosis
What cells are ganglioneuromas derived from?
Neural crest cells
- Ganglion cells
- Schwannian stroma
What is the most common caue of isolated hypoaldosteronism?
Hyporeninemic hypoaldosteronism
(Type IV renal tubular acidosis)
What is the name for a catecholamine-producing tumro in the…
Adrenal medulla?
Outside of the adrenal medulla?
- Adrenal medulla: pheochromocytoma
- Produces epinephrine
- Outside of the adrenal medulla: paraganglioma
- Produces norepinephrine
What is the embryonic origin of the adrenal medulla?
Neural crest cells
Describe the characteristics of NFM-1 (5)
- Neurofibroma
- Café-au-lait spots
- Iris harmatoma
- Axillary and inguinal freckling
- Pheochromocytoma in ~2%
What genetic mutation is associated with MEN-2?
How is it inherited?
Germline point mutation in the RET proto-oncogene
Autosomal dominant