Adrenal Incidentaloma AND Workup

The answer first

An adrenal incidentaloma is a mass above 1 cm found on imaging done for something else. Every encounter answers two questions in sequence: is it malignant, and is it hormonally active? Imaging drives the first, biochemistry drives the second, and three thresholds decide everything — 10 HU, 50 nmol/L, and 4 cm.^[1][2]

The FRACP candidate defends those three numbers under fire: 10 HU is the unenhanced CT cut-off for a benign lipid-rich adenoma; 50 nmol/L is the post-dexamethasone cortisol that defines mild autonomous cortisol secretion (MACS); 4 cm is the size where adrenocortical carcinoma risk jumps and surgical excision enters the conversation.^[1][5]

References11ShowHide

1. [1]Fassnacht M, Tsagarakis S, Terzolo M et al. European Society of Endocrinology clinical practice guidelines on the management of adrenal incidentalomas, in collaboration with the European Network for the Study of Adrenal Tumors European journal of endocrinology, 2023.PMID 37318239
2. [2]Fassnacht M, Arlt W, Bancos I et al. Management of adrenal incidentalomas: European Society of Endocrinology Clinical Practice Guideline in collaboration with the European Network for the Study of Adrenal Tumors European journal of endocrinology, 2016.PMID 27390021
3. [3]Rowe NE, Kumar R, Schieda N et al. Diagnosis, Management, and Follow-Up of the Incidentally Discovered Adrenal Mass: CUA Guideline Endorsed by the AUA The Journal of urology, 2023.PMID 37556768
4. [4]Morelli V, Palmieri S Adrenal incidentaloma: differential diagnosis and management strategies Minerva endocrinologica, 2019.PMID 29808642
5. [5]Terzolo M, Osella G, Alì A et al. Subclinical Cushing's syndrome in adrenal incidentaloma Clinical endocrinology, 1998.PMID 9509073
6. [6]Vieira-Correa M, Giorgi RB, Oliveira KC et al. Saliva versus serum cortisol to identify subclinical hypercortisolism in adrenal incidentalomas: simplicity versus accuracy Journal of endocrinological investigation, 2019.PMID 31456173
7. [7]Araujo-Castro M, Calatayud Gutiérrez M, Parra Ramírez P et al. Update of the guidelines on the management of adrenal incidentaloma from the adrenal group of the Spanish society of endocrinology and nutrition (SEEN) Endocrine, 2025.PMID 40906030
8. [8]Lee JM, Kim MK, Ko SH et al. Clinical Guidelines for the Management of Adrenal Incidentaloma Endocrinology and metabolism (Seoul, Korea), 2017.PMID 28685511
9. [9]Sahdev A Recommendations for the management of adrenal incidentalomas: what is pertinent for radiologists? The British journal of radiology, 2017.PMID 28181818
10. [10]Terzolo M, Pia A, Alì A et al. Adrenal incidentaloma: a new cause of the metabolic syndrome? The Journal of clinical endocrinology and metabolism, 2002.PMID 11889151
11. [11]Reimondo G, Allasino B, Bovio S et al. Pros and cons of dexamethasone suppression test for screening of subclinical Cushing's syndrome in patients with adrenal incidentalomas Journal of endocrinological investigation, 2011.PMID 20634637