Adrenal Incidentaloma
This post-1-mg dexamethasone suppression test serum cortisol value is the standard diagnostic cutoff used to rule out autonomous cortisol secretion in an incidentaloma.
What is ≤1.8 μg/dL (or 50 nmol/L)?
This specific autoimmune marker should be checked in all patients newly diagnosed with primary adrenal insufficiency to assess for autoimmune adrenalitis.
What is a 21-hydroxylase antibody?
Unlike the low-dose dexamethasone suppression test, these two initial screening options bypass the diagnostic challenge of altered cortisol-binding globulin (CBG) levels caused by oral contraceptives or pregnancy.
What are late-night salivary cortisol and 24-hour urine free cortisol tests?
This specific screening profile—consisting of a plasma aldosterone concentration to plasma renin activity (PAC/PRA) ratio—is considered a positive screen strongly suggestive of primary aldosteronism.
What is a PAC/PRA ratio greater than 20 (with a PAC greater than 15 ng/dL)?
This high-sensitivity diagnostic test is preferred over urine collections when clinical suspicion for pheochromocytoma is extremely high, but it requires the patient to rest quietly in a supine position for 20-30 minutes prior to draw.
What is plasma free metanephrines?
On an unenhanced CT scan of an incidental adrenal mass, an attenuation value at or below this threshold effectively excludes malignancy and a pheochromocytoma, identifying a benign lipid-rich adenoma.
What is 10 Hounsfield Units (HU)?
This is the minimum peak serum total cortisol level required at 30 or 60 minutes during a high-dose (250 μg) cosyntropin stimulation test to formally rule out adrenal insufficiency.
What is 18 μg/dL?
This rare and aggressive malignancy often presents with rapid-onset Cushing syndrome, virilization/hyperandrogenism, and an irregular adrenal mass typically larger than 4 cm on CT.
What is adrenocortical carcinoma (ACC)?
This potassium-sparing diuretic is the preferred medical management for patients with bilateral adrenal hyperplasia or those with a unilateral adenoma who are poor surgical candidates.
What is spironolactone?
Beyond symptomatic presentation, endocrine guidelines state that biochemical screening for pheochromocytoma is explicitly indicated for any completely asymptomatic patient who possesses this specific radiologic or genetic risk factor.
What is an adrenal incidentaloma with a density greater than 10 Hounsfield Units (HU) or a known predisposing germline mutation?
This autonomous hormone secretion pattern is confirmed when a patient with an incidentaloma has a post-LDST cortisol level greater than 1.8 μg/dL and a suppressed morning ACTH, but completely lacks the specific features of overt Cushing syndrome.
What is mild autonomous cortisol secretion (MACS)?
This endocrine disorder, if left untreated, dictates that its specific hormone replacement therapy must never be initiated before administering glucocorticoids, in order to avoid precipitating an acute adrenal crisis.
What is primary (or central) hypothyroidism?
This is the mandatory initial surgical management for localized adrenocortical carcinoma (ACC), preferred over a laparoscopic approach due to the high risk of capsular rupture and local tumor seeding.
hat is an open surgical resection (or open adrenalectomy)?
In a patient with confirmed primary hyperaldosteronism who desires surgical management, this diagnostic procedure is critical to differentiate a unilateral aldosterone-producing adenoma from bilateral adrenal hyperplasia.
What is adrenal vein sampling (AVS)?
To maximize diagnostic sensitivity, this screening test requires the patient to remain in a quiet, supine position for 20 to 30 minutes prior to phlebotomy to minimize stress-induced false positives.
What is a plasma free metanephrines test?
For a lipid-poor adrenal mass with an unenhanced CT density greater than 10 HU, this minimum percentage of absolute contrast washout at 15 minutes is required to radiologically classify the lesion as benign.
What is 60%?
In an acute inpatient setting, a senior resident should suspect this catastrophic condition if unexpected, refractory hypotension and back pain develop in a patient with a known hypercoagulable state or one undergoing therapeutic anticoagulation.
What is bilateral adrenal hemorrhage?
This specific medication interaction can cause a false-positive result on an overnight low-dose dexamethasone suppression test by inducing hepatic CYP3A4 enzymes and rapidly clearing the dexamethasone.
What are anti-epileptic drugs (such as phenytoin, carbamazepine) or pioglitazone?
Per endocrine guidelines, one can bypass formal confirmatory suppression testing and diagnose primary aldosteronism directly if a patient presents with spontaneous hypokalemia, a suppressed renin level, and this minimum threshold of plasma aldosterone concentration (PAC).
What is a PAC greater than 20 ng/dL?
Because pathologic findings cannot reliably predict metastatic potential, this long-term surveillance strategy is required annually for patients following tumor resection.
What is annual biochemical screening (plasma free metanephrines)?
In a patient with a known extra-adrenal malignancy and a newly discovered, indeterminate adrenal mass, this diagnostic procedure can confirm a metastasis but is strictly contraindicated until a pheochromocytoma is biochemically excluded.
What is a percutaneous/CT-guided needle biopsy?
Patients who abruptly stop using unverified, over-the-counter animal-derived adrenal extracts for "adrenal fatigue" are at high risk for acute adrenal crisis due to this underlying physiological mechanism.
What is prolonged exogenous suppression of the hypothalamic-pituitary-adrenal (HPA) axis?
A 24-hour urine collection for free cortisol can yield a false-positive result in patients with severe polyuria exceeding this daily fluid volume, regardless of true adrenal status.
What is 5 liters per day?
During a confirmatory oral sodium loading test, primary hyperaldosteronism is diagnosed if a 24-hour urine collection shows an aldosterone excretion rate greater than 12 µg/24h alongside this mandatory urinary sodium validation metric.
What is a urinary sodium excretion greater than 200 mEq/24h (confirming adequate salt loading)?
This specific, irreversible, long-acting non-selective alpha-adrenergic antagonist is the gold-standard drug of choice used to prepare a patient with a pheochromocytoma for surgical resection.
What is phenoxybenzamine?