Prevention & care

Adrenal incidentalomas: unexpected masses, imaging and hormones, mild cortisol secretion, biopsy, and follow-up

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An adrenal incidentaloma is a mass discovered during imaging for another reason, rather than a suspected adrenal disorder. The name describes how it was found. It does not establish cancer, excess hormones, an operation requirement or a harmless result.[1]

An incidental finding is a discovery category

The 2023 ESE guideline uses a strict definition: imaging was not arranged for suspected adrenal disease. Masses found during hereditary-syndrome surveillance or cancer staging have different contexts, considered separately. Why the scan was ordered changes pretest risk and interpretation, even when two reports use the same word “mass.”[2]

Two different questions guide assessment

Two different questions guide assessment
Question	What it concerns
Benign or malignant?	The nature of the growth and its imaging characteristics.[1]
Functioning or nonfunctioning?	Whether it produces excess hormones.[1]
Do these classifications coincide?	A noncancerous growth can still be hormonally active.[1]

Not every adrenal growth is the same tissue problem

The Endocrine Society lists adenomas, adrenal cancer, cancer spread from another site, cysts and less common lesions containing fat or blood-forming tissue. A descriptive scan finding is therefore not one uniform disease. Both malignant and benign growths can produce hormones, and more than one hormone may be involved.[1]

The assessment combines imaging, history and selected hormone tests

The ESE leaflet pairs hormone evaluation through clinical assessment and selected blood/urine tests with imaging characterization. Noncontrast CT is first-line; MRI or PET can serve particular remaining questions.[3]

Density and uniform appearance matter together

The 2023 guideline says a homogeneous mass with unenhanced CT density at or below 10 Hounsfield units needs no further imaging. These are technical radiologist-assessed conditions, not an instruction to ignore every adrenal finding or apply one number from a contrast-enhanced report.[2]

The testing plan is selected rather than one compulsory panel

The same guideline addresses dexamethasone suppression for cortisol autonomy and metanephrine testing for lesions not typical of a benign adenoma. Hormone investigations and imaging classification are linked but distinct. A symptom checklist, random cortisol or a scan image alone cannot replace the appropriate evaluation.[2]

Mild autonomous cortisol secretion differs from overt Cushing features

The ESE leaflet describes cortisol overproduction without the characteristic overt Cushing pattern as mild autonomous cortisol secretion, or MACS. Hypertension, diabetes and bone fragility can still matter. “Mild” describes a category; it does not certify that all health consequences are absent or that surgery will improve every associated condition.[3]

Follow-up depends on the findings rather than the word incidentaloma

The leaflet explains that clearly benign, nonfunctioning findings can need no further investigation, whereas unusual imaging or hormone excess may require a multidisciplinary decision or repeat assessment. Bilateral or multiple lesions can require additional tests. Ask which question follow-up will answer and which change would alter management.[3]

Biopsy is not the automatic next step

The 2022 American Association of Endocrine Surgeons guidance reserves biopsy for unusual circumstances where results would change management, after assessment excludes hormone excess. It also calls for hormonal evaluation when another cancer is already present. An adrenal needle sample is not a substitute for an endocrine safety assessment.[4]

The ESE leaflet notes that an adrenal mass during another cancer’s evaluation is not automatically a metastasis. The underlying cancer and imaging characteristics matter. Different diagnostic pathways reflect different questions, not a rule that all unexpected adrenal growths must be biopsied.[3]

CHIRACIC tested selected hypertensive patients with unilateral MACS

CHIRACIC randomized 52 eligible adults to adrenalectomy or conservative management after a standardized blood-pressure assessment and treatment run-in. It was open-label and followed participants for 13 months. The primary endpoint combined normal home blood pressure with reduced antihypertensive treatment: 46% versus 15%, with adjusted risk difference 34 percentage points.[6]

The confidence interval for that difference was 11–58 points. Surgery-related serious events were reported in three operated participants; both groups had other serious events. French public health and German research funding supported the trial. The result concerns selected unilateral MACS with hypertension, not every incidentaloma or lifetime survival.[6]

Evidence & uncertainty

Guidelines separate malignancy assessment from hormone assessment. Selected trials support some blood-pressure benefits from surgery in mild cortisol secretion, while broader metabolic benefits remain less certain. A complete current synthesis and qualified review remain unfinished.[2][6][7]

Selected-source overview · Independent review pending

Published questions

Does an adrenal incidentaloma diagnosis itself mean adrenal cancer?

Selected-source overview · Independent review pending. Read the evidence context.

It describes a mass found unexpectedly, not its final biological classification.[1]

Evidence behind this answer

Adrenal Incidentaloma
professional association explanation · 2022
Selected relevant original official page passages inspected · January 2022: discovery, distinct activity/cancer classifications, structural causes and discussion questions