Diagnostic Imaging Pathways - Adrenal Mass (Incidental On CT)

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This pathway provides guidance for further investigating adult patients with an incidental adrenal mass detected on computed tomography.

Date reviewed: January 2012

Date of next review: January 2015

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1a Click to view full size image

Adrenal Adenoma

Image 1a, b and C (Computed Tomography): There is a 12mm sized rounded hypodense mass lesion noted in the right adrenal gland. There is marked contrast wash-out (absolute percentage washout of 77%) demonstrated in the lesion which is in keeping with adenoma.

1b Click to view full size image
1c Click to view full size image
2a Click to view full size image

Adrenocortical Adenoma

Image 2a: Adrenalectomy specimen showing a typical adrenocortical adenoma forming a circumscribed and encapsulated mass with a homogenous yellow cut surface. Note the residual adrenal parenchyma at the periphery of the lesion (arrows).

2b Click to view full size image Image 2b (H&E, x2.5) and 2c (H&E, x10): Histological sections showing the pushing border between the adenoma and the surrounding parenchyma (arrows). At higher power, the cells form sheets and nests and exhibit uniform nuclei and clear cytoplasm due to their high lipid content.
2c Click to view full size image
3a Click to view full size image

Adrenal Myelolipoma

Image 3a and 3b (Computed Tomography): Axial and coronal CT views demonstrating a low attenuation right adrenal lesion containing dark fat density (arrow) and higher attenuation myeloid tissue.

3b Click to view full size image
4a Click to view full size image Adrenal Haemorrhage (Waterhouse-Friedrickson syndrome)

Image 4a and 4b (Computed Tomography): Pre- and post-contrast images showing bilateral adrenal haemorrhage (arrows) and extension into the surrounding tissues on the right.

4b Click to view full size image

Teaching Points

Teaching Points

  • Incidental adenomas ("incidentalomas") are found in up to 5% of scans done for other indications
  • The first stage in investigating the significance of the mass is biochemical screening for Cushing's Syndrome, Phaeochromocytoma and Hyperaldosteronism
  • CT is the initial imaging modality to investigate the characteristics of the mass
  • The aim of imaging is to determine whether the mass is a carcinoma, as early identification can lead to biopsy and potentially curative surgical resection
  • Follow-up of a lesion, to assess growth characteristics as well as biochemical activity is crucial



  1. Young WF Jr. Management approaches to adrenal incidentalomas. Endocrinol Metab Clin North Am. 2000;29(1):159-85. (Review article)
  2. Herrera MF, Grant CS, van Heerden JA, et al. Incidentally discovered adrenal tumours: an institutional perspective. Surgery. 1991;110(6):1014-21. (Level II evidence)
  3. Barry MK, van Heerden JA, Farley DR, et al. Can adrenal incidentalomas be safely observed? World J Surg. 1998;22:599-604. (Level III evidence)
  4. McNicholas MM, Lee MJ, Mayo-Smith WW, et al. An imaging algorithm for the differential diagnosis of adrenal adenomas and metastases. AJR Am J Roentgenol. 1995;165:1453-9. (Level III evidence)
  5. Pender SM, Boland GW, Lee MJ, et al. The incidental nonhyperfunctioning adrenal mass: an imaging algorithm for characterisation. Clin Radiol. 1998;53:796-804. (Review article)
  6. Lee MJ, Hahn PF, Papanicolaou N, et al. Benign and malignant adrenal masses: CT distinction with attenuation coefficients, size, and observer analysis. Radiology. 1991;179:415-8. (Level III evidence)
  7. Boland GWL, Lee MJ, Gazelle GS, et al. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR Am J Roentgenol. 1998;171:201-4. (Level II evidence) Click here to view reference
  8. Korobkin M, Brodeur FJ, Francis IR, Quint LE, Dunnick NR, Londy F. CT time-attenuation washout curves of adrenal adenomas and nonadenomas. AJR Am J Roentgenol. 1998;170:747-52. (Level II/III evidence)
  9. Bulow B, Jansson S, Juhlin C et al. Adrenal incidentaloma: follow-up results from a Swedish prospective study. Eur J Endocrinol. 2006;154:419-23. (Level II Evidence) Click here to view reference
  10. Heinz- Peer G, Honigschnabl S, Schneider B, et al. Characterization of adrenal masses using MR imaging with histopathologic correlation. AJR Am J Roentgenol. 1999;173:15-22. (Level II evidence) Click here to view reference
  11. Lee MJ, Mayo-Smith WW, Hahn PF, et al. State-of-the-art MR imaging of the adrenal gland. Radiographics. 1994:14:1015-32. (Review article)
  12. Welch TJ, Sheedy PF, Stephens DH, et al. Percutaneous adrenal biopsy: review of a 10-year experience. Radiology. 1994;193:341-4. (Level III evidence)
  13. Silverman SG, Mueller PR, Pinkney LP, et al. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology. 1993;187:715-8. (Level III/IV evidence)
  14. Candel AG, Gattuso P, Reyes CV, et al. Fine needle aspiration biopsy of adrenal masses in patients with extra-adrenal malignancy. Surgery. 1993;114(6):1132-7. (Level III evidence)
  15. Graham DJ, Mc Henry CR. The adrenal incidentaloma: guidelines for evaluation and recommendations for management. Surg Oncol Clin N Am. 1998;7:749-64. (Guideline document)
  16. Young F The incidentally discovered adrenal mass. N Engl J Med. 2007;356(6):601-8. (Review article)
  17. Angeli A, Osella G, Ali A et al. Adrenal incidentaloma: an overview of clinical and epidemiological data from the National Italian Study Group. Horm Res. 1997;47:279-83. (Level II evidence) Click here to view reference
  18. Yun M, Kim W, Alnafisi N, Lacorte L, Jang S, Alavi A. 18F-FDG PET in characterizing adrenal lesions detected on CT or MRI. J Nucl Med. 2001;42:1795-99. (Level III evidence)
  19. Szolar DH, Kammerhuber FH. Adrenal adenomas and nonadenomas: assessment of washout at delayed contrast-enhanced CT. Radiology. 1998;207:369-75. (Level III evidence)
  20. Hamrahian AH, Iochimescu AG, Remer EM et al. Clinical utility of noncontrast computed tomography attenuation value (Hounsfield units) to differentiate adrenal adenomas/hyperplasia from nonadenomas: Cleveland Clinic experience. J Clin Endocrin Metab. 2005;90:871-7. (Level II evidence)
  21. Pena CS, Boland GW, Hahn PF, Lee MJ, Mueller PR. Characterization of indeterminate (lipid-poor) adrenal masses: use of washout characteristics at contrast-enhanced CT. Radiology. 2000;217:798-802. (Level III evidence)
  22. Caoili EM, Korobkin M, Francis IR, Cohan RH, Dunnick NR. Adrenal masses: characterization with combined unenhanced and delayed enhanced CT. Radiology. 2002;222:629-33. (Level III evidence)
  23. Bae KT, Fuangtharnthip P, Prasad SR et al. Adrenal masses: CT characterization with histogram analysis method. Radiology. 2003;228:735-42. (Level I evidence) Click here to view reference
  24. Mantero F, Terzolo M, Arnaldi G et al. A survey on adrenal incidentaloma in Italy. J Clin Endocrinol Metab. 2000;85:637-44. (Level III evidence)
  25. Grumbach MM, Beverly MK, Braunstein GD et al. Management of the clinically inapparent adrenal mass ("incidentaloma"). Ann Intern Med. 2003;138:424-9. (Review article) Click here to view reference
  26. Terzolo M, Bovio S, Reimondo G et al. Subclinical Cushing's syndrome in adrenal incidentalomas. Endocrinol Metab Clin North Am. 2005;34:423-39. (Review article) Click here to view reference
  27. Tauchmanova L, Rossi R, Biondi B et al. Patients with subclinical Cushing's syndrome due to adrenal adenoma have increased cardiovascular risk. J Clin Endocrinol Metab. 2002;87:4872-8. (Level IV evidence)
  28. Bovio S, Cataldi, Reimondo G et al. Prevalence of adrenal incidentaloma in a contemporary computerized tomography series. J Endocrinol Invest. 2006;29:298-302. (Level II evidence) Click here to view reference
  29. Mengden T, Hubmann P, Muller J et al. Urinary free cortisol versus 17-hydroxycorticosteroids: a comparative study of their diagnostic value in Cushing's Syndrome Clinical Invest. 1992;70(7):545-8. (Level III evidence)
  30. Song J, Chaudhry FS, Mayo-Smith WW. The incidental adrenal mass on CT: prevalence of adrenal disease in 1,049 consecutive adrenal masses in patients with no known malignancy. AJR Am J Roentgenol. 2008;190(5):1163-8. (Level II evidence) Click here to view reference
  31. Boland GWL, Blake MA, Hahn PF et al. Incidental adrenal lesions: principles, techniques and algorithms for imaging characterization. Radiology. 2008;249(3):756-75. (Review article)

Further Reading

  1. Teeger S, Papanicolaou N, Vaughan ED Jr. Current concepts in imaging adrenal masses. World J Urol. 1999;17:3-8. (Review article)
  2. Barzon L, Boscaro M. Diagnosis and management of adrenal incidentalomas. J Urology. 2000;163:398-407. (Review article)
  3. Boland G, Blake M, Hahn P, Mayo-Smith W. Incidental adrenal lesions: principles, techniques and algorithms for imaging characterisation. Radiology. 2008;249:756-75. (Review article)

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