Adrenal insufficiency from metastatic colonic carcinoma masquerading as isolated aldosterone deficiency. Report of a case and review of the literature.

A case of adrenal insufficiency secondary to metastatic colonic carcinoma is reported. Because the patient was taking prednisone for an unrelated condition, his initial presentation mimicked isolated aldosterone deficiency with an elevated serum potassium of 8.7 mmol/l. Cortisol deficiency was documented by ACTH testing. The diagnosis of metastatic disease causing adrenal insufficiency was suspected after a computed body scan of the abdomen revealed marked bilateral adrenal enlargement. Adrenal insufficiency secondary to metastatic cancer is reviewed.