To the Editor.
—We read with particular interest case No. 10 (occult ectopic adrenocorticotropic hormone [ACTH] secretion with thymic hyperplasia) in a recent article in the Archives by Findling and Tyrrell1 because it presented similarities with a patient we have treated. Our patient (36 years of age) presented in November 1983 with the classic features of Cushing's disease. Evaluation showed the patient's adrenal cortisol production to be relatively nonsuppressible with high-dose (8 mg/d) dexamethasone therapy. A computed tomographic (CT) scan of the pituitary gland was normal, and the suspected ectopic source of ACTH could not be found. (Computed tomographic scans of the patient's chest and abdomen were normal except for bilateral adrenal hyperplasia). Sampling of petrosal sinus, jugular veins, and superior and inferior vena cava, in January 1984 suggested a nonpituitary source of ACTH. Further workup for an ectopic source of ACTH, including celiac angiography, was, again, negative.