Assessment of incidental adrenal mass

Question 1

Most common tumor in adults

Answer 1

Adrenal masses

Question 2

Etiology

Answer 2

41% adenomas
14% metastasis
10% adrenocortical Ca

Question 3

Differential

Answer 3

Common-> non-secreting adrenal adenoma

Uncommon->
Cushing's
Phaeochromocytoma
Primary hyperaldosteronism
Adrenal cyst, myelolipomas, hemangiomas, ganglioneuroma
Granulomatous infiltration
Adrenocortical Ca
Adrenal mets
Adrenal malignant melanoma

Question 4

Clinical assessment

Answer 4

Clinical signs of hormone overproduction
Cushings
Phaeochromocytoma
Primary hyperaldosteronism
Mass effect->abdominal pain

Question 5

Features of primary hyperaldosteronism

Answer 5

Hypertension
Muscle cramps/weakness
Cardiac arrythmias
Hypokalemia induced nephrogenic diabetes insipidus

Question 6

Initial Investigations

Answer 6

Electrolytes: hypokalaemia may suggest hyperaldosteronism; hypokalaemia may be present in Cushing’s syndrome.

Fasting lipid profile: hyperlipidaemia may be present in Cushing’s syndrome.

Fasting blood glucose: hyperglycaemia may be present in Cushing’s syndrome or phaeochromocytoma.

FBC: leukocytosis with neutrophilia may occur in Cushing’s syndrome.

Screening test for Cushing’s syndrome with late night salivary cortisol or overnight (1 mg) dexamethasone suppression test (OST).

Screening for phaeochromocytoma with fractionated plasma metanephrines.

Patients with HTN should also have plasma renin/aldosterone ratio measured to assess for hyperaldosteronism.

Question 7

If screening for hormone activity positive, further testing

Answer 7

For Cushing’s syndrome, 24-hour urine free cortisol and early morning (9 am) serum corticotropin (ACTH).

For phaeochromocytoma, 24-hour urine total metanephrines and fractionated catecholamines.

For hyperaldosteronism, plasma aldosterone concentration on an unrestricted salt diet, 24-hour urinary aldosterone excretion, and saline infusion test (saline suppression test

Question 8

Imaging

Answer 8

CT with contrast and MRI

FDG-PET

Question 9

Features of benign on imaging

Answer 9

Homogenous

Question 10

Features of malignancy on imaging

Answer 10

Irregular shape
Calcification
Tumor necrosis
>4cm
>20HU on unenhanced CT
Delay in contrast medium washout
Metastatic->bilateral

Question 11

Manegemtn

Answer 11

Surgical
Imaging evaluation at 6-12 months
Biochemical testing annually

Question 12

Growth suggestive of malignancy

Answer 12

> 2cm/year