The Case for High-Dose Dexamethasone Suppression Testing Preoperatively in Aldosterone-Producing Adenoma to Exclude Cosecretion of Cortisol

nature publishing group COMMENTARY T he case report by Rossi and coworkers in this issue of the journal 1 contains important messages, and in discussion raises interesting issues. First, adrenal tumors can cosecrete more than one hormone, in this case cortisol as well as aldosterone in a patient with Conn's syndrome. Second, when unilateral adrenalectomy is performed for a tumor secreting cortisol, steroid cover is required, and was given in the reported case. Although chronic renin–angiotensin suppression can lead to perioperative and postoperative hyper-kalemia, this is not usually life threatening, but unexpected Addisonian crisis can be. In the reported case, a 30-year history suggested possible postoperative hyperkalemia, but the patient had received spironolactone for long enough to relieve profound renin suppression, and the contralateral adrenal was likely to soon resume aldosterone secretion. Third, adrenal venous sampling to decide whether autonomous secretion of aldosterone is unilateral, widely employed in Conn's syndrome (but not performed in this patient), employs the ratio of aldosterone to cor-tisol in the adrenal veins and in a peripheral vein. This may be difficult to interpret when cortisol secretion by the contralateral adrenal is suppressed, and even more so with bilateral macroad-enomas. 2 Fourth, full recovery of the contralateral adrenal from long-term pituitary-adrenal suppression (described 50 years ago by Grant Liddle's group) can take at least 9 months, which may not have been anticipated but is clearly illustrated in the patient's progress. 1 Great skill is required in giving just enough glucocor-ticoid replacement to keep the patient well, but little enough to stimulate adrenocorticotropic hormone (ACTH) secretion which will hasten recovery. With long duration of resistant hypertension and age 62 years, continuing requirement for antihypertensive therapy at 9 months is not unexpected in this patient. The tumor consisted mainly of clear, presumably zona fasciculata–type cells with scattered areas of compact, presumably glomerulosa or reticularis-type cells, and the authors speculate that the former could have secreted aldosterone, and the latter cortisol. Fasciculata–type cells are involved in aldos-terone secretion in both glucocorticoid-suppressible, Familial Hyperaldosteronism Type-I and the first-described Conn's adenomas, in both cases unresponsive to upright posture and angiotensin infusion. 3 Atypical adenomas with excessive aldos-terone secretion responsive to upright posture and angiotensin may contain a significant proportion of glomerulosa-type cells. 3,4 The response of aldosterone to upright posture would have been of interest in the reported case, in regard to which cells secreted aldosterone. When large adrenal macroadenomas are …