Conn's Syndrome ΓÇô Radiolabelled Cholesterol Test
The administration of radiolabelled cholesterol can also be used to distinguish between an adenoma and hyperplasia, since the labelled cholesterol is taken up only by the adenoma (Fig. 10.7). This is in contrast to the bilateral uptake found in patients with idiopathic hyperplasia. Scans may have to be performed after dexamethasone administration to suppress uptake by normal glucocorticoid-secreting cells. In some patients, misleading results can be obtained- if spironolactone has been used as long-term therapy before the scan is performed. In such patients, adenomas can be missed as there may be bilateral uptake.
