Selective Venous Sampling to Differentiate Ectopic ACTH Secretion from Pituitary Cushing's Syndrome

Abstract

Ectopic ACTH secretion may be indistinguishable from pituitary-dependent Cushing's syndrome (Cushing's disease) by current diagnostic tests.1 2 3 With increasing application of pituitary treatment for Cushing's disease, it becomes essential to distinguish between these entities. We report the use of selective catheterization and venous sampling to localize ACTH secretion in a patient with a perplexing clinical and laboratory picture compatible with either ectopic ACTH secretion or pituitary-dependent Cushing's syndrome.Case ReportOver a 14-month period a 25-year-old soldier noted centripetal obesity, bruising, emotional lability, profound weakness and wide, deeply pigmented, bronze striae. The blood pressure was 230/140 mm Hg, and he had . . .