Functioning adrenal adenoma in association with congenital adrenal hyperplasia

We report a case of a young hypertensive male who was first seen in 1998 with a right thalamic haemorrhage and uncontrolled hypertension. CT abdomen showed a right adrenal tumour and a hyperplastic left adrenal gland. Laparoscopic adrenalectomy performed followed by histopathological examination confirmed the diagnosis of adrenal adenoma. He subsequently presented to us again a year later with persistent hyperkalaemia and asymptomatic hyponatraemia. Further investigations strongly suggested the presence of isolated mineralocorticoid deficiency with normal cortisol levels. This was confirmed to be due to partial or late-onset congenital adrenal hyperplasia (CAH). We discuss the association of partial CAH and adrenal tumours and the unmasking of the mineralocorticoid deficiency following adrenalectomy.