Adrenal Incidentaloma

Question 1

What is an incidentaloma?

Answer 1

An adrenal mass, usually > 1 cm, found incidentally on abdominal imaging

Question 2

What do ALL solid adrenal masses require, once discovered?

Answer 2

Functional screening/workup

Question 3

Are solid adrenal masses more likely malignant, benign functional, or benign non-functional?

Answer 3

Benign non-functional adenomas (80%)

Question 4

What CT w/wo contrast findings lead you to making a conclusion an adrenal adenoma is more likely benign vs. malignant?

Answer 4

1. CT wo contrast Hounsfield units < 18
2. CT w contrast, washout > 60% at 15 minutes
3. Size less than 6 cm
   * doesn’t distinguish b/w functional vs. non-functional

Question 5

Name 3 on the most common functional adenomas

Answer 5

1. Cushing’s syndrome (cortisol producing adenoma)
2. Pheochromocytoma (epi producing adenoma)
3. Conn’s syndrome (aldosterone producing adenoma)

Question 6

If a adenoma is malignant, what is it most likely to be?

Answer 6

Metastatic lesion!!!

• If there is a known primary, > 50% likelihood all solid adrenal masses will be metastatic diseases

Question 7

The majority of adrenal cortical carcinoma are functional/non-functional

Answer 7

Functional

Question 8

If an adrenal adenoma is < 4 cm, likelihood it is malignant is:

Answer 8

4%

Question 9

Adrenal adenoma is 4-6cm, likelihood it is malignant is:

Answer 9

6%

Question 10

If adrenal adenoma is > 6 cm, likelihood it is malignant is:

Answer 10

> 25%

Question 11

How much does CT scan underestimate tumor size?

Answer 11

1 cm!

- therefore, if there is a 5cm adrenal adenoma on CT, best treat it like a 6cm adenoma (surgically remove it)