1. Pituitary Gland
Thyrotoxicosis
Adrenal Gland
Thyroid/Parathyroid
Bone Health
Skin + Heart
$100
$100
$100
$100
$100
$200
$200
$200
$200
$200
$300
$300
$300
$300
$300
$400
$400
$400
$400
$400
$500
$500
$500
$500
$500

2. Adrenal $100 1.5 cm mass found on CT Scan 1 mg overnight DST cortisol is 3.3 mg/dL↑

3. What is a mild autonomous cortisol excess (MACE) adrenal adenoma?

4. Mild Autonomous Cortisol Excess (MACE)
15-20% of patients with incidentally discovered adrenal tumors have MACE
MACE patients lack classical physical features of overt Cushing’s syndrome i.e. striae, thinning of the skin
Patients with MACE at higher risk of developing type 2 DM, hypertension, dyslipidemia, obesity, and fractures
MACE associated with an increased risk of cardiovascular events
50% of patients see metabolic improvement with adrenalectomy

5. Increased Cardiovascular Events the Higher the 8 AM Cortisol
Prevalence of cardiovascular events (CVE) among the whole sample of patients subdivided in quartiles on the basis of cortisol levels at 08:00 h after 1 mg-dexamethasone suppression test (1 mg-DST). In patients with cortisol after 1 mg-DST above 1.5 μg/dL, the CVE prevalence progressively increased with increasing cortisol levels. The CVE prevalence was similar between I and II quartiles (9.3% and 9.4% respectively) and between the II and IV quartiles (21.8% and 28.9% respectively) whereas it was significantly higher in the III and IV quartiles as compared with I and II quartiles, P = 0.01 for both comparisons.
European Journal of Endocrinology 2017;177:73-83

6. Adrenal Incidentaloma Definition
“Mass lesion greater than 1 cm in diameter discovered “accidentally” during a radiographic examination performed for indications other than an evaluation for adrenal disease.”
Management of the clinically inapparent adrenal mass (incidentaloma). NIH State-of-the-Science Conference Statement Feb 4-6, 2002.

7. Adrenal Incidentaloma— Two Important Questions
Is the adrenal mass hormonally active?
Is the adrenal mass benign or malignant?

8. CT numbers in Hounsfield Units (HU)
Sir Godfrey Newbold Hounsfield
CT numbers in Hounsfield Units (HU), with water at the zero (0) point, range from negative (-) 1000 for air to plus (+) approximately 3000 for dense bone.
Since CT number values are strongly related to tissue densities the various tissues and materials are distributed along the scale according to their density. It is this difference in densities that is the source of the physical contrast that will be converted and displayed as visible contrast in the images.
To a great extent, the very high contrast sensitivity of CT is derived from the ability to select a small range of CT numbers and display them over the full brightness range (dark black to bright white) in the image. This occurs during the third phase of the process and can be controlled by the person viewing the image.
The range of CT numbers to be displayed in the image is designated as the WINDOW. The two adjustable protocol factors that control the window are the LEVEL and the WIDTH.
The LEVEL control sets the midpoint of the window range along the CT number scale. It can be used to optimize the image contrast for viewing different anatomical regions. A relative low window might be used for seeing the contrast within the lungs and a high window to see contrast within bones.
The WIDTH setting is very much of an image contrast control. Reducing the window width increases the contrast among tissues as they are displayed in an image.
HU <10 on unenhanced CT = benign adenoma 100%

9. Hounsfield Units
9.8 HU = benign adenoma

10. Magnetic Resonance Imaging
Equally effective as CT.
Adenomas are isointense with the liver on T2 weighted images.
Carcinomas are hyperintense compared to the liver on T2 weighted images.

11. Magnetic Resonance Imaging— T2 Weighted Images
Isointense
Benign
Hyperintense
Malignant
Note the vascular and inhomogenous imaging characteristics of this mass

12. Adrenal Incidentaloma Take Home Messages
Adrenal masses (incidentalomas) are common and they increase in frequency with age
Adrenal masses may be benign (non-functional), malignant (primary or metastatic), or functional (pheochromocytoma, Cushing’s, aldosteroma or sex-hormone secreting).
Size matters as does the amount of attenuation (Hounsfield Units) in determining whether the mass is benign or malignant.