In two female patients with hypothalamic-hypophyseal Cushing's syndrome who had not taken oral contraceptives, upper abdominal sonography showed three liver tumours as chance findings. In one case the left lobe was involved alone and in one case both lobes. None of the three tumours could be demonstrated by means of computer assisted tomography. Autopsy in one case and liver arteriography and scan in other other led to the diagnosis of focal nodular hyperplasia of the liver. These cases demonstrate the importance of sonography in the recognition of liver tumours. A connection between the overpopulation of adrenocorticosteroids and the formation or enlargement of focal nodular hyperplasia of the liver cannot be excluded.