Observations and Comments on Failure of Dexamethasone Suppression

IN most patients with Cushing's disease∥ urinary 17-hydroxycorticosteroids (17OHCS) are readily suppressed by 8 mg. of dexamethasone per day. However, Liddle,1 in 1960, predicted that the excessive amounts of cortisol in some cases of this disease would not be suppressible with this amount of dexamethasone, and in 1962, Scott and his associates2 reported such a case. There have been reports of other patients with bilateral adrenocortical lesions with high levels of cortisol resistant to dexamethasone suppression.3 4 5 6 7 8 9 10 Failure to appreciate the variable significance of this phenomenon and the previous unavailability of plasma ACTH assays have resulted in the divergent interpretations of . . .