Adrenal adenoma with excess secretion of corticosterone and 18-hydroxycorticosterone

A 64-year-old man with sudden onset of quadriplegia due to marked hypokalemia was referred to our clinic with suppressed plasma renin activity in the presence of a low aldosterone level. Computerized tomography demonstrated a left adrenal adenoma, shown on adrenal scintigraphy to be functioning. The elevated basal level of plasma corticosterone and its increased response to 1-24 adrenocorticotropic hormone suggested the tumor produced corticosterone. The surgical specimen was a benign adrenocortical adenoma with excess content of corticosterone and 18-hydroxycorticosterone.