Module 5: Endocrine: Adrenal Cortical Adenoma, Pheocyto Flashcards
First starting off, what is an adrenal cortical adenoma?
- -Unilateral
- -Non-functional (asymptomatic) called an incidentaloma
- -Benign neoplasm of the adrenal glands – is usually non functional but can be functional
Describe the functional aspect of adrenal cortical adenoma
Zona Fasciculata — cortisol production —-Cushings (ACTH low due to negative feedback so contralateral adrenal atrophy)
Zona Glomerulosa – aldosterone (Conn’s syndrome) –primary hyperaldosteronism
Zona Reticularis– androgens
men: gynecomastia
women: virilization and hirsutism and FCC and endometrial cancer due to the excess estrogen made by the androgens
What is the triad of symptoms if a patient develops Conn’s Syndrome in the Zona Glomerulosa?
- Malignant Hypertension: resorption of sodium and water in the distal tubule; normal sodium levels and low renin levels (neg feedback)
- Hypokalemia (muscle cramps and weakness)
- Metabolic Alkalosis
What is secondary aldosteronism?
From outside the adrenal gland
–renin and aldosterone are both elevated
What are causes of secondary aldosteronism?
- Hypoperfusion
- Renal Artery Stenosis
- Liver Cirrhosis (no albumin production– fluid trapped in tissues — hypoperfusion to kidneys –renin secretion)
- Nephrotic Syndrome: albumin is lost in the urine (fluid trapped in tissues – hypoperfusion to kidneys–renin secretion)
- Congestive Heart Failure
Moving on to pheochromacytoma, what is the etiology?
Etiology: Tumor of adrenal medulla (chromaffin cells)
cell of origin: chromaffin neural crest cells (benign or malignant) (NOT ENTEROCHROMAFFIN thats GI)
Catecholamine production
What is the rule of 10 in pheochromacytoma?
10% malignant
10% extraadrenal
10% in children
20-25% familial (MEN 2A, MEN 2B, VHL, Neurofibromatosis)
–what else do VHL? Retinal and Cerebellar Hemangioblastomas and Clear Cell Renal Carcinoma
What is the presentation for a patient with pheochromocytoma?
Mimics hyperthyroidism and Graves
- -episodic malignant hypertension
- -anxiety
- -sweating
- -palpitations (most common cause of death)
- -diarrhea
What makes the symptoms worsen in pheochromocytoma?
exercise Pressure on abdomen Stress Surgery --all due to the release of catecholamines
What investigations are done for pheochromocytoma?
Never do a CT first
Elevated catecholamines in the blood and urine
BMA and metanephrines in the urine are catecholamine metabolites
–VMA is catecholamine metabolite for neuroblastoma
–Metanephrine is catacholamine metabolite for pheochromocytoma
CT is next of adrenal to locate: 10% is extra adrenal and 90% is adrenal medulla.. what if you see nothing??
not found there—-MIBG (radioisotope scan) —Carotid Bodies typically (this is the most likely location of extra adrenal sites)
What is seen on gross and histology for pheochromocytoma?
Gross: Brown is taking over the medulla (takes over the entire adrenal gland)
Histology: Nests of spindle shaped chromaffin cells separated by scanty vascularized stroma (Zellballen)
What are the complications in pheochromocytoma?
HTN – atherosclerosis — hypertrophy of LV— LV failure — RV failure – mural thrombosis— atrial fibrilation – emboli stroke
Arrhythmias is the most common cause of death
What should happen in surgery patients with pheochromocytoma?
Should be alpha blocked then beta blocked
–alpha receptors on blood vessels — vasoconstriction – stroke MI
alpha blocks allow vasodilation
beta receptors are located on the heart (if blocked first, all catecholamines would go to alpha receptors and cause massive vasoconstriction)
The primary etiology of HTN in endocrine disorders is idiopathic. However, what are some secondary causes?
Acromegaly: GH upregulates alpha 1 receptors
Cushing’s Disease: cortisol is weak mineralcorticoid and upregulation of alpha 1 receptors
Pheochromocytoma: production of epinephrine and norepinephrine
Conn’s Syndrome: due to adrenal cortical adenoma affecting ZG
Next we will briefly discuss neuroblastoma in kids. What is a neuroblastoma?
Poorly differentiated tumor of NCCs that normally give rise to the adrenal medulla and sympathetic ganglia due to germline mutation in ALK gene.
–second most common solid malignant tumor in children