[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Conditions](https://durgical.com/en/conditions/) › Adrenal incidentaloma [Conditions](https://durgical.com/en/conditions/) · [Endocrinology](https://durgical.com/en/conditions/) # Adrenal incidentaloma An adrenal lump found by chance on a scan done for another reason. Most are harmless, but each needs hormone tests and a check that it is not cancer. Updated 2026-11-01 ## Structures involved Tap one to see what it is and open it in 3D. - [Right adrenal gland](https://durgical.com/en/anatomy/suprarenal-gland-abdomen/) - [Left adrenal gland](https://durgical.com/en/anatomy/suprarenal-gland/) - [Adrenal arteries](https://durgical.com/en/anatomy/middle-suprarenal-artery/) - [Kidneys](https://durgical.com/en/anatomy/kidney/) - [Liver](https://durgical.com/en/anatomy/liver/) - [Inferior vena cava](https://durgical.com/en/anatomy/inferior-vena-cava/) ## Why it happens - [Benign vs malignant tumours: the comparison table](https://durgical.com/en/general-pathology/benign-vs-malignant-tumours-the-comparison-table/) - [The HPA axis and its circadian rhythm](https://durgical.com/en/physiology/the-hpa-axis-and-its-circadian-rhythm/) - [Measuring hormones: stimulation and suppression tests](https://durgical.com/en/physiology/measuring-hormones-stimulation-and-suppression-tests/) - [Adrenal cortex zones and medulla](https://durgical.com/en/histology/adrenal-cortex-zones-and-medulla/) ## What it is An adrenal mass, usually 1 cm or larger, discovered on imaging performed for a reason other than suspected adrenal disease. The two questions in every case are whether it secretes hormones and whether it is malignant. ## Who gets it Found in a few per cent of abdominal CT scans, and more often with age (over 5 to 7% of people older than 70). Its detection has risen with the wider use of CT in Colombia and the rest of Latin America. Most are benign non-functioning cortical adenomas. ## Causes - Non-functioning adrenocortical adenoma (most common) - Adenoma with autonomous cortisol secretion (mild cortisol excess without full Cushing features) - Aldosterone-producing adenoma and pheochromocytoma - Adrenocortical carcinoma and metastases (lung, breast, [kidney](https://durgical.com/en/anatomy/kidney/), melanoma, lymphoma) - Myelolipoma, cyst, haemorrhage and granulomatous infection (tuberculosis, histoplasmosis) ## Risk factors - Older age - Obesity, type 2 diabetes and hypertension (associated with adenomas) - Known extra-adrenal cancer (raises the chance of metastasis) ## Pathophysiology Most incidentalomas are clonal benign growths of the adrenal cortex rich in intracellular lipid, which makes them low-density on unenhanced CT. Some secrete cortisol independently of ACTH; even modest excess raises the risk of hypertension, diabetes, osteoporosis and cardiovascular events. Malignant lesions are usually larger, lipid-poor and heterogeneous, and grow over time. ## Classification - By function: non-functioning, autonomous cortisol secretion, primary aldosteronism, pheochromocytoma - By imaging: benign-appearing (homogeneous, 10 Hounsfield units or less on unenhanced CT) versus indeterminate - By size: under 4 cm versus 4 cm or more, which raises concern for carcinoma ## Symptoms and signs - Usually none; found on a scan for abdominal pain, trauma or cancer staging - Subtle features of cortisol excess: weight gain, hypertension, hyperglycaemia, bone loss - Resistant hypertension or low potassium suggesting aldosterone excess - Episodes of headache, sweating and palpitations suggesting pheochromocytoma - Flank pain or weight loss with large or malignant masses ## Red flags - Mass of 4 cm or more, or with heterogeneous, lipid-poor features on CT - Rapid growth on follow-up imaging - Paroxysmal hypertension or a hypertensive crisis (possible pheochromocytoma) - Rapid-onset virilisation or signs of cortisol excess in a large mass (adrenocortical carcinoma) - Bilateral masses with signs of adrenal insufficiency ## Diagnosis **Clinical** History and examination for hypertension, Cushing features, virilisation, adrenergic episodes and known cancer; review of the imaging that found the mass. **Tests** Every patient: 1 mg overnight dexamethasone suppression test for autonomous cortisol secretion and plasma or urine metanephrines for pheochromocytoma (metanephrines can be omitted if the mass is clearly lipid-rich adenoma on CT). Aldosterone-to-renin ratio if there is hypertension or low potassium. Sex steroid precursors if carcinoma is suspected. Biopsy is rarely needed and only after pheochromocytoma is excluded. **Imaging** Unenhanced CT is the key test: a homogeneous mass of 10 Hounsfield units or less is a benign adenoma. Indeterminate masses are assessed with contrast washout CT, chemical-shift MRI or FDG-PET. ## Differential diagnosis - Adrenocortical carcinoma - Metastasis to the adrenal gland - Pheochromocytoma - Adrenal haemorrhage or cyst - Pseudo-adrenal masses: upper pole renal lesion, splenic lobule, vessel or gastric diverticulum ## Goal of treatment Identify the few masses that are malignant or hormonally active and treat them, while sparing the many benign non-functioning adenomas from unnecessary surgery and repeated tests. ## Treatment **Surgical** Adrenalectomy, usually laparoscopic, for functioning tumours (pheochromocytoma, aldosterone-producing adenoma, overt Cushing syndrome), suspected carcinoma or indeterminate masses that grow; selected cases of autonomous cortisol secretion with related disease. **Medical** Preoperative alpha-blockade for pheochromocytoma; perioperative glucocorticoid cover after removal of a cortisol-secreting adenoma because the other adrenal is suppressed. Treatment of hypertension, diabetes and bone loss in non-operated patients with mild cortisol excess. **Follow-up** Benign-appearing small non-functioning adenomas need no further imaging. Indeterminate masses are re-imaged at about 6 to 12 months. Mild cortisol excess is reviewed for its metabolic complications. ## Complications - Missed pheochromocytoma causing a hypertensive crisis during surgery or biopsy - Cardiometabolic disease from autonomous cortisol secretion - Adrenal insufficiency after removal of a cortisol-secreting adenoma - Delayed diagnosis of adrenocortical carcinoma or metastasis ## Prognosis Excellent for benign non-functioning adenomas, which rarely grow or become active. Prognosis is driven by the underlying lesion when it is a carcinoma or metastasis. ## Test yourself Think of the answer, then tap the question to see it. ## Which two questions must be answered for every adrenal incidentaloma? Is it hormonally active, and is it malignant? ## Which unenhanced CT finding confirms a benign lipid-rich adenoma? A homogeneous mass with attenuation of 10 Hounsfield units or less. ## Which screening test detects autonomous cortisol secretion? The 1 mg overnight dexamethasone suppression test. ## Why must pheochromocytoma be excluded before adrenal biopsy or surgery? Manipulation can release catecholamines and trigger a hypertensive crisis. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/conditions/adrenal-incidentaloma/) ## Related conditions - [Cushing syndrome](https://durgical.com/en/conditions/cushing-syndrome/) - [Phaeochromocytoma](https://durgical.com/en/conditions/phaeochromocytoma/) - [Primary hyperaldosteronism (Conn syndrome)](https://durgical.com/en/conditions/primary-hyperaldosteronism/) - [Adrenal insufficiency](https://durgical.com/en/conditions/adrenal-insufficiency/) - [Adrenal crisis](https://durgical.com/en/conditions/adrenal-crisis/) - [Arterial hypertension](https://durgical.com/en/conditions/arterial-hypertension/) - [Type 2 diabetes mellitus](https://durgical.com/en/conditions/type-2-diabetes-mellitus/) - [Osteoporosis](https://durgical.com/en/conditions/osteoporosis/) - [Obesity](https://durgical.com/en/conditions/obesity/) - [Lung cancer](https://durgical.com/en/conditions/lung-cancer/) - [Tuberculosis](https://durgical.com/en/conditions/tuberculosis/) - [Histoplasmosis](https://durgical.com/en/conditions/histoplasmosis/) Educational information, not medical advice. For any symptom, see a health professional. Sources: [ESE Clinical Practice Guideline on the management of Adrenal Incidentalomas, in collaboration with the European Network for the Study of Adrenal Tumors](https://www.ese-hormones.org/publications/directory/ese-clinical-practice-guideline-on-the-management-of-adrenal-incidentalomas-in-collaboration-with-the-european-network-for-the-study-of-adrenal-tumors/) (European Society of Endocrinology, 2023); [Nonfunctional Adrenal Masses - Endocrinology - MSD Manual Professional Edition](https://www.msdmanuals.com/professional/endocrine-and-metabolic-disorders/adrenal-disorders/nonfunctional-adrenal-masses) (MSD Manual Professional Edition, 2025). [← All conditions](https://durgical.com/en/conditions/) ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/conditions/adrenal-incidentaloma/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/conditions/adrenal-incidentaloma/