Primary adrenocortical nodular dysplasia presented as adrenal adenoma by functional scintigraphy

This is a report of a case of a 12-year-old boy with Cushing's syndrome in which high doses of dexamethasone failed to suppress glucocorticoid secretion. Neither CT nor MRI (morphologic studies) revealed any adrenal abnormality. Functional images with NP-59 (I-131 beta-iodomethyl-norcholesterol) clearly revealed intense unilateral uptake in the right adrenal gland. A right adrenalectomy was performed, and the pathologic diagnosis was primary adrenocortical nodular dysplasia. One year later, the cushingoid signs had virtually disappeared and urinary steroid excretion and serum cortisol levels were within the normal range. Nevertheless, primary adrenocortical nodular dysplasia is essentially a bilateral disease. In this case, a remission in the adrenocortical hyperfunction was observed. Although there was confusion in the etiological diagnosis, functional scintigraphy correctly indicated the status of adrenal function.