A CASE OF SILENT 21-HYDROXYLASE DEFICIENCY WITH PERSISTENT ADRENAL INSUFFICIENCY AFTER REMOVAL OF AN ADRENAL INCIDENTALOMA

A case of an adrenal incidentaloma in a 57-year-old man with silent 21 -hydroxylase deficiency is reported. Abdominal computed tomography rev ealed a right adrenal tumour of 6cm in diameter. There was no evidence of adrenal hormone excess. However, after surgical removal of the adr enal tumour, the patient developed acute adrenal insufficiency, Adreno cortical function has remained low ever since surgery. Pathological ex amination of the tumour revealed a cortical adenoma. On the basis of i ncreased plasma renin activity and serum 17 alpha-hydroxyprogesterone concentration and decreased 21-hydroxylase activity of the adenoma tis sue, the patient was diagnosed as having systemic 21-hydroxylase defic iency. There are two possible mechanisms for the persistent adrenal in sufficiency; first the residual left adrenal gland may have been origi nally hypo-functioning for some reason and; second, the left gland may have lost the ability to regenerate following prolonged suppression b y the adenoma. In cases of adrenal incidentalomas with 21-hydroxylase deficiency, the indications for surgical removal should be carefully c onsidered.