Background: Adrenal incidental masses (incidentalomas) are present in up to 10% of patients. The majority of these adrenal masses are clinically inapparent, but may be functionally active in a significant proportion; thus assessment by endocrinologists is essential.
We assessed the functionality of adrenal incidentalomas referred to the endocrinology team at the Queen Elizabeth Hospital in Gateshead.
Methods: Patients with adrenal incidentalomas that were referred to the endocrine team between January 2008 and August 2009 were identified. Patient notes, laboratory results, images and radiological reports were reviewed.
Results: Sixty-two patients (27 females) were referred to the endocrinologists with a finding of an incidental adrenal nodule with sizes ranging between 6 and 42 mm. Twenty-nine (47%) patients had left sided tumours, 23 (37%) were on the right and 10 (16%) were bilateral. All patients underwent a series of hormonal investigations: 94% had 24 h cortisol levels measured, 87% had an overnight dexamethasone suppression test, 95% had urinary metadrenalines measured and aldosterone/ renin activity was measured in 90% of patients.
The largest group of patients (87%) were found to have benign non-functional adenomas. One patient had a phaeochromocytoma, 1 had a cortisol secreting adrenal mass, and 6 (10%) patients were found to have sub-clinical Cushings syndrome. No patients were found to have primary hyperaldosteronism. Four (6%) patients (one with overt Cushings syndrome, one with a phaeochromocytoma and two with subclinical Cushings) underwent definitive surgical management.
Conclusions: Nearly 13% of patients that are referred with adrenal incidentalomas are functional on subsequent endocrine evaluation. Potentially serious conditions such as phaeochromocytomas and overt Cushings syndrome can be identified and treated. However, the most common functional abnormality is subclinical Cushings syndrome for which there is current lack of sufficient evidence regarding its long term management.