Adrenal

High Yield Anatomy Vascular supply

• Superior: phrenic artery
• Middle: aorta
• Inferior: renal artery Left vein drains into left renal vein, right vein drains into the IVC Adrenal Cortex (Mesoderm) +Medulla (Ectoderm) Neuroendocrine in origin chromaffin cells
• Zona Glomerulosa: “Salt” - regulates aldosterone
• Zona Fasicularis: “Sugar”- glucocorticoids
• Zona Reticularis: “Sex”- androgens/estrogen Incidentaloma:
• 1-2% found incidentally on imaging
• Concerning features of >4-6 cm, >10 HU, enlarging, and functioning
• Always look for functioning tumors before biopsy
• Send urine urine metanephrines/VMA/catecholamines, urinary hydroxycorticosteroids, serum K with plasma renin and aldosterone levels

Congenital Adrenal Hyperplasia

• 21 and 11 beta hydroxylase are crucial to convert cholesterol to aldosterone, cortisol, and testosterone
• 21 hydroxylase deficiency: increased testosterone and decreased aldosterone
• 11 hydroxylase deficiency: increased testosterone and increased aldosterone
• 17 hydroxylase deficiency: decreased testosterone and increased aldosterone Hyperalderosteronism: Conn’s syndrome
• Hypertension because of sodium preservation and K wasting
• Primary: renin low, Secondary: renin high
• Plasma aldosterone: renin >25
• Bilateral idiopathic adrenal hyperplasia is MC reason in 60- 65% (manage medically)
• Dx: with salt load suppression test, urine aldosterone will remain elevated
• Localize on CT, MRI, NP-59 scintigraphy or Adrenal venous sampling
• Tx: spironolactones, CCB like nifedipine and K replacement
• Surgery: adrenalectomy
• If bilateral, will need fludrocortisone postoperatively Hypocortisolism (Addison’s disease)
• Decreased cortisol and aldosterone with high ACTH
• Dx: cosyntropin testing- cortisol remains low

• Acute Adrenal insufficiency: refractory hypotension, fevers, lethargy, pain, N/V

• Tx: Dexamethasone, fluids
• Chronic: Give corticosteroids Hypercortisolism Cushing’s syndrome
• Most commonly exogenous
• Measure 24-hour cortisol or urinary cortisol and late-night cortisol
• ACTH low—look for adrenal adenoma
• Adrenalectomy when dx on CT scan
• ACTH high—look for pituitary tumors (Cushing’s DISEASE) or ectopic producer like small cell lung cancer
• Cushing’s disease: #1 cause, Brain MRI followed by transsphenoidal approach resection
• Ectopic ACTH: #2 cause, CT CAP, resection Adrenocortical Carcinoma
• Typically present at advanced stages, rare malignancy
• Very aggressive, patients present with Cushing syndrome, virilization and HTN
• Radical adrenalectomy with debulking, mitotane for adjuvant/ recurrent disease Pheochromocytoma
• Rule of 10: 10% are malignant, bilateral, in children, familial, and extra-adrenal
• Only adrenal pheochromocytomas will produce epinephrine because of PNMT enzyme
• Can be seen on MIBG (when imaging does not show mass)
• Preoperative prep included volume replacement, alpha blockade with phenoxybenzamine or prazosin, followed by beta blockade
• Tx: adrenalectomy (ligate adrenal veins first to avoid spillage)
• Additional sites are paragangliomas; MC is organ of Zuckerkandl

Quick Hits

• Clonidine suppression test for patients with suspected pheochromocytoma but normotensive
• MC reason for Cushing Syndrome - Exogenous steroids
• MC reason for Addison Disease (adrenal insufficiency) - Autoimmune (1st world) or Tuberculosis (3rd world)

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