An adrenal incidentaloma is an adrenal tumor that is discovered on an imaging test that is being done for a problem unrelated to adrenal disease. Adrenal tumors found as part of the work-up or follow-up of cancer are very likely to be adrenal metastases and do not count as adrenal incidentalomas. As imaging techniques have improved and become more commonly used, doctors are finding more and more adrenal incidentalomas. The chance of having an adrenal incidentaloma increases with increasing age. At the age of 50, there is a 3% risk of having an adrenal incidentaloma and this goes up to 7% by the age of 70. While most adrenal incidentalomas do not cause health problems, they must be evaluated because a small percentage can lead to significant disease.
Adrenal incidentalomas fall into one of three categories:
- Functioning tumors – these tumors make too much of any of the hormones that the adrenal glands normally make and include aldosterone-producing adenomas (See Primary Hyperaldosteronism), cortisol producing tumors (See Cushing's Syndrome), adrenaline producing tumors (See Pheochromocytoma), or sex-hormone producing tumors (See Sex-hormone Producing Tumors).
- Malignant tumors – these tumors include adrenocortical cancer and metastatic disease.
- Benign, non-functional tumors – these tumors include adenomas, myelolipomas, ganglioneuromas, adrenal cysts, and hematomas.
In general, tumors that are functional, malignant, and/or large should be removed.