Adrenal incidentalomas

Question 1

what is an adrenal incidentaloma?

Answer 1

mass>1 cm in diameter and found incidentally on radiology studies

Need to rule out risk of malignancy and assess for subclinical endocrine activity

Question 2

CT fingings that suggest malignancy for adrenal incidentaloma

Answer 2

bilateral or large (>4cm) lesions,
irregular or inhomogenous morphology, contrast enhancement with delayed contrast washout
high radiographic attenuation

Question 3

attenuation is expressed in Hounsfield units (HU)

Answer 3

estimates the radiodensity of a lesion.

Low attenuation lesion <10 HU) have high lipid content are usually benign adenomas

High attenuation lesions >20 HU are more likely to represent adrenal metastasis, adrenaocortical carcinoma, or pheochromocytoma

Question 4

metabolic evaluation of adrenal incidentaloma should

Answer 4

screen for pheochromocytoma (plasma (high likelihood) or urinary (low likelihood) metanephrines and catecholamines.

Screen for Cushings syndrome (overnight dexamethasone suppression test)

Hyperaldosteronism (plasma aldosterone and plasma renin activity)

Question 5

classic triad of pheochromocytoma

Answer 5

paroxysmal headache, sweating, tachycardia

Question 6

pts who have functional adrenal masses should

Answer 6

be evaluated for surgical resection

also consider this for large tumors >4cm too.

Question 7

non functioning adenomas should get

Answer 7

serial CT and biochemical testing surveillance

Question 8

needle biospy of a vascular adenal adenoma

Answer 8

never. it can cause hemorrhage and hypertensive crisis. needs biochemical testing prior and can seed if it’s a adrenalcortical carcinoma

Question 9

CT imaging features that suggest malignant potential for an adrenal incidentaloma

Answer 9

> 10 Hounsfield units, mass >4cm and >50% contrast retention seen after 10 minutes after contrast administration.

Question 10

initial tests to order for adrenal incidentaloma to rule out functional or not?

Answer 10

overnight dexamethasone suppression test (Cushing’s dx)
urinary catecholamines and metanephrines (Pheochromocytoma)
aldosterone to renin ratio (if hypertensive, don’t need to order if not hypertensive)

Question 11

if positive functional testing for adrenal incidentaloma consider this next step:

Answer 11

confirm mass is source of hormone excess before considering surgery

Question 12

if biochemical testing is negative for adrenal incidentaloma consider this next step: AND or large tumor then

Answer 12

if has large tumor but negative functional, consider FNA or surgery or close follow up.

If <4cm and negative needs conservative follow up.

Question 13

why don’t we order 24 hr urine free cortisol for a incidental adrenal adenoma?

Answer 13

we prefer the overnight 1 mg dexamethasone suppression test because more sensitive

the 24 hr urine cortisol is not sensitive enough to pick up on a subclinical Cushings syndrome.

Question 14

in the context of an incidental adrenal adenoma that has been found, if concerned for subclinical cushing syndrome then several tests that must be followed after a positive 1mg dexamethasone suppression test is

Answer 14

DHEAs, urine free cortisol, and 8 mg overnight dexamethasone suppresion test are required to confirm autonomous cortisol secretion.

Question 15

primary hyperaldosteronism positive screening test is if?

Answer 15

plasma aldosterone - plasma renin ratio ARR >20

high aldosterone and low renin ratio.