Hypokalemia Due to Ectopic Adrenocorticotropic Hormone.

Hypokalemia is a common disorder in clinical practice. The underlying pathophysiology can be attributed to 3 main mechanisms: insufficient potassium intake, excessive urinary or gastrointestinal losses, and transcellular shift. Renal loss is the most common cause of hypokalemia. Renal loss of potassium can occur due to diuretics, mineralocorticoid excess or hypercortisolism (Cushing syndrome). Among patients with Cushing syndrome, ectopic adrenocorticotropic hormone (ACTH) is the most frequent cause. We present a case of hypokalemia and hypertension due to ectopic ACTH production leading to Cushing syndrome.