The American Association of Endocrine Surgeons, Patient Education Site

Adrenal incidentaloma

This document is available in Spanish

Treatment: What is the best treatment?

Patients with a functional tumor (i.e. making too much hormoneHormone - a chemical made by a gland that travels in the bloodstream and "tells organs what to do.") should have an operation to remove the adrenal gland and tumor. For patients with non-functional tumors, the size of the tumor and imaging characteristics will determine if an operation is indicated. If the tumor has suspicious characteristics on imaging (i.e. irregular borders, evidence of invasion, etc), then it should be removed. In 2002, the National Institutes of Health released a consensus statement with the following guidelines for who should have an adrenalectomyAdrenalectomy - an operation to remove the adrenal gland based on the size of the tumor:

Size of TumorRisk of CancerRecommendation
Less than 4 cm2 to 3%Observation
4 to 6 cm7%Adrenalectomy (if the patient is healthy enough)
Greater than 6 cm25%Adrenalectomy

For tumors between 4 and 6 cm in size, the general recommendation is to remove it, but the patient's age, other health problems, and imaging characteristics of the tumor should be taken into consideration. If there are reasons the patient may not tolerate an operation, then observation is the best treatment. Since CAT scan and MRI underestimate the size of adrenal tumors (i.e. the adrenal tumors are often bigger in the operating room than on CAT scan), many physicians use slightly different size criteria and recommend observing tumors less than 3 cm, removing any tumor greater than 5 cm, and removing tumors between 3 and 5 cm if the patient is healthy enough. (See How is adrenal surgery performed?)

Treatment: What is the follow-up?

If the tumor is not removed, it is important to have close follow-up to see if the tumor becomes functional or if it grows. Studies have shown that most adrenal incidentalomas that are observed will not grow or become hyperactive. Only 5 to 25% grow, while 3 to 4% shrink. While up to 20% of tumors will become functional, it is unlikely to happen in tumors smaller than 3 cm. The risk that a tumor will become hyperactive is greatest in the first 3 to 4 years and Cushing's syndromeCushing's syndrome - a disease where too much cortisol is being made is the most likely problem to develop.

For patients who are being followed for adrenal incidentalomaAdrenal incidentaloma - an asymptomatic adrenal tumor that is discovered on an imaging test (CAT scan, MRI, etc) which was ordered to evaluate a problem that is unrelated to adrenal disease., the National Institutes of Health recommend:

  1. repeat CAT scan 6 to 12 months after diagnosis
  2. repeat hormoneHormone - a chemical made by a gland that travels in the bloodstream and "tells organs what to do." testing every 12 months for 5 years
    (including low dose dexamethasone suppression test, plasma metanephrines, and plasma aldosteroneAldosterone - a mineralocorticoid that controls blood pressure/renin)

If the tumor does not grow after the first year, then repeat CAT scan may not be necessary.


Find an Experienced Endocrine Surgeon


Visit Endocrine Patient Resources Page