Recommended evaluation of adrenal incidentalomas is costly, has high false-positive rates and confers a risk of fatal cancer that is similar to the risk of the adrenal lesion becoming malignant; time for a rethink?
OBJECTIVE
To assess the performance of current clinical recommendations for the evaluation of an adrenal incidentaloma. DESIGN AND METHODS LITERATURE REVIEW: Electronic databases (Pubmed, Ovid and citation searches from key articles) from 1980 to 2008 were searched. Eligible studies were those deemed most applicable to the clinical scenario of a patient referred to an endocrinologist for assessment of an incidentally detected adrenal mass. Surgical series, histopathological series and oncological series were reviewed and most were excluded.


RESULTS
The prevalence of functional and malignant lesions presenting as adrenal incidentaloma was similar to that quoted in most reviews, other than a lower incidence of adrenal carcinoma (1.9 vs 4.7%) and metastases (0.7 vs 2.3%). The development of functionality or malignancy during follow-up was rare (<1% becoming functional and 0.2% becoming malignant). During follow-up, false-positive rates of the recommended investigations are typically 50 times greater than true positive rates. The average recommended computed tomography (CT) scan follow-up exposes each patient to 23 mSv of ionising radiation, equating to a 1 in 430 to 2170 chance of causing fatal cancer. This is similar to the chance of developing adrenal malignancy during 3-year follow-up of adrenal incidentaloma.


CONCLUSIONS
Current recommendations for evaluation of adrenal incidentaloma are likely to result in significant costs, both financial and emotional, due to high false-positive rates. The dose of radiation involved in currently recommended CT scan follow-up confers a risk of fatal cancer that is similar to the risk of the adrenal becoming malignant. This argues for a review of current guidelines.
Cawood
T J
TJ
Department of Endocrinology, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand. tom.cawood@cdhb.govt.nz
Hunt
P J
PJ
O'Shea
D
D
Cole
D
D
Soule
S
S
D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000191:economics* / Q000453:epidemiology; D002471:Cell Transformation, Neoplastic; D003480:Cushing Syndrome / Q000473:pathology; D018450:Disease Progression; D005189:False Positive Reactions; D005500:Follow-Up Studies; D017408:Guidelines as Topic; D006801:Humans; D006929:Hyperaldosteronism / Q000175:diagnosis; D010673:Pheochromocytoma / Q000175:diagnosis; D011859:Radiography / Q000009:adverse effects