[A diagnostic maze: Cushing's disease].

The case of a 78-year-old female presenting to the authors' department with heart failure with dyspnea at minimal exertion (NYHA III) as well as hypertensive blood pressure and hypokalaemia is reported. Laboratory workup showed hypercortisolism. Further workup, including imaging studies and selective catheterisation of the inferior petrosal sinus, resulted in the diagnosis of Cushing's disease caused by a pituitary microadenoma.