Nodular adrenal hyperplasia and Cushing's syndrome

Clinical, biochemical, operative, and postmortem findings have established nodular adrenal hyperplasia as a clinicopathologic entity and a cause of Cushing's syndrome. The possibility exists that there is a relationship among the various forms of adrenal and pituitary diseases that lead to hyperadrenocorticism. This may include a continuous sequence from bilateral adrenal hyperplasia to micronodular and macronodular hyperplasia to a unilateral adrenocortical adenoma and even carcinoma. We report the investigation and management of six patients with Cushing's syndrome caused by bilateral nodular adrenal hyperplasia who were treated by operation at the Glasgow Royal Infirmary, Scotland from 1975 to 1979. Investigations included a variety of biochemical and radioimmunoassay tests on plasma and urine, provocative and inhibition tests, scanning (ultrasonography, computed tomography, and iodocholesterol), arteriography, and selective venous sampling. All patients underwent a bilateral adrenalectomy by the posterior approach. The adrenal glands varied in size from 4.9 to 18 gm and histology showed that they had the features of bilateral nodular adrenal hyperplasia. Five patients did well after operation; they are presently receiving replacement steroid therapy, and at a 3- to 7-year follow-up there was no evidence of Nelson's syndrome. Advances in drug therapy (medical adrenalectomy) with aminoglutethimide, metyrapone, and O,p-DDD should not at present cause a change in our surgical approach to this condition.