Adrenal Nodules

ADRENAL NODULES

Nodules on the adrenal glands are a common finding: around 3 to 5 percent of healthy persons. Most are discovered incidentally as part of an unrelated diagnostic test such as a CT scan or MRI imaging of the abdomen. Most patients with adrenal nodules are completely asymptomatic.

Adrenal nodules should be evaluated by an experienced endocrinologist to ask two questions:

  1. Is the nodule malignant (cancerous)?
  2. Is the nodule hormonally active?

Assessing Malignant Potential

The vast majority of adrenal nodules (also referred to as adrenal adenomas) are benign. It is still very important to exclude cancer in each patient with an adrenal adenoma. Malignant potential is best evaluated by radiographic diagnostic imaging using CT scanning or MRI. Size of the adrenal nodule is a very important consideration. Over 90% of adrenal carcinomas are greater than 4 cm in size. But, since adrenal cancer is uncommon, most large adrenal nodules are still benign. It is usually necessary to repeat the diagnostic imaging of the adrenal nodule 3–6 months after its initial discovery. Nodules that increase in size over a 3–6 month period of observation are also worrisome. Most experts recommend surgical resection of a nodule that is > 4 cm in size or if the nodule shows a significant increase in size during surveillance.

Assessment of Hormonal Secretion

Up to 15% of adrenal adenomas are over-producing hormones. This can result in a variety of endocrine syndromes including Cushing’s syndrome (overproduction of cortisol), primary hyperaldosteronism (or Conn’s syndrome due to overproduction of aldosterone), or pheochromocytoma (overproduction of adrenaline). Such conditions may be associated with a variety of symptoms or clinical manifestations. A careful medical history, physical examination as well as measurement of adrenal hormones in blood, urine or saliva is needed to exclude a hormonally active adrenal nodule.

Monitoring and Treatment

Adrenal nodules that have low risk for malignancy and are not hormonally active are usually monitored closely and not surgically removed. If the nodule is > 4 cm in size, increases in size during surveillance or has worrisome characteristics on imaging, removal of the affected gland is usually recommended. In most cases this can be performed laparoscopically. Hormonally active adrenal adenomas may be treated medically (with medications), surgically or with a combination of both techniques, depending on the hormones involved and the severity of the over-production.