Villous adenoma with hyponatremia and syncope: report of a case

A case of villous adenoma of the colon with hyponatremia, hypovolemia, and syncope is presented. The correct diagnosis was delayed because of the prevailing idea that villous adenomas are associated with hypokalemia. The patient recovered fully after surgical removal of one of the largest villous adenomas reported in the literature. Sodium loss may be the dominant feature of this syndrome. Villous adenoma has to be included among the causes of hyponatremia.