Approach to adrenal incidentalomas : a review

Abstract

Adrenal tumours are nowadays most often discovered incidentally, on imaging not performed for suspected adrenal disease that are termed adrenal incidentalomas. There are two questions clinicians need to explore: whether the lesion is benign or malignant (relying mostly on radiology) and whether it is functional or not (relying on biochemical tests). An unenhanced CT scan (CT without contrast) or MRI is the imaging modality of choice. However if an incidentaloma is discovered on a CT with contrast, done for other reasons than suspected adrenal pathology, contrast washout may be helpful in diagnosing a benign lesion. Functional analysis in patients confirmed to have an adenoma or rarely an adrenal carcinoma should include tests to exclude cortisol excess, and in patients with hypertension mineralocorticoid excess. The production of subtle amounts of cortisol; not enough to cause classical clinical features of Cushing’s syndrome, but enough to cause metabolic disturbances and possibly increased mortality, has over recent years gained more attention. In those patients with suspected phaeochromocytoma, plasma free metanephrines or urinary fractionated metanephrines should be checked. This review, based on recent literature, discusses the evidence based suggested algorithms for investigating adrenal incidentalomas.