Background: Adrenal incidentalomas (AI) are a common radiological finding (estimated prevalence 4%). Guidelines from the American Association of Clinical Endocrinologists (AACE) and the American Association of Endocrine Surgeons (AAES) recommend radiological evaluation at 36 months then annually for 12 years, and hormonal evaluation by measurement of plasma aldosterone/renin (ARR) activity, 24 h catecholamines/metanephrines (CATS), and 1 mg overnight dexamethasone suppression test (ONDST).
Aims: To compare the prevalence of AI reported on abdominal CT scans at our institution with the literature and to identify how many patients were referred for endocrine review. To compare our management of AI with the AACE/AAES guidelines.
Methods: An electronic search of all radiology reports for CT scans incorporating the abdomen and undertaken at our Health Board between 2005 and 2010 was performed using the search terms adrenal incidentaloma, adrenal mass, adrenal myelolipoma, adrenal adenoma and adrenal hyperplasia. Patients were subsequently assigned to one of 5 categories based on case note/report review: no adrenal mass, adrenal metastasis, primary adrenal malignancy, AI, radiological investigation for known endocrine disorder.
Results: 1153/28 809 scans were positive for the search criteria; 504 were excluded as they had no adrenal mass, 98 were excluded for malignancy (94 metastasis, 4 primary) and 27 as they were being investigated for a known endocrine disorder. This left 475 with a diagnosis of AI (prevalence 1.65%) but only 17% were referred for endocrine review, of whom 95% had appropriate repeat radiology (no malignancy and only 4 reported a change in lesion size). 77% (ARR), 88% (CATS) and 92% (ONDST) were evaluated biochemically; subclinical Cushings syndrome was the commonest hormonal abnormality (16%).
Conclusions: The reported prevalence of AI is lower at our centre compared with the referenced literature and only a small proportion of patients are referred appropriately for endocrine review.