Appraisal of Adrenocortical Hyperfunction: Patients with Cushing's Syndrome or “Non-endocrine” Tumors

Abstract

The degree of adrenocortical hyperfunction has been investigated biochemically in 17 patients with orthodox Cushing's syndrome and 8 patients with adrenocortical overactivity associated with tumors of non-endocrine organs. Of the indices examined, the secretion rate of cortisol was consistently abnormal. The urinary excretion of free cortisol was frequently abnormal, but excretion of 17-ketosteroids, 17-ketogenic steroids and levels of plasma cortisol were much less so. The response of urinary 17-ketogenic steroids to intramuscular administration of corticotropin was variable, being only occasionally excessive and thus of value in the assessment of the adrenal. Suppression of the adrenal steroid output by dexamethasone was of value in patients with adrenocortical “hyperplasia,” particularly regarding the failure of these patients to show suppression with low doses. Strikingly abnormal results indicative of cortisol overproduction were obtained in the patients with non-endocrine tumors. The importance of demonstration of abnormality in at least 2 of the indices studied in the diagnosis of Cushing's syndrome, especially in its early phases, is stressed. In a given individual there is a quantitative relationship between secretion rate of cortisol and excretion of its metabolites as urinary 17-ketogenic steroids, but this relationship varies among individuals. Follow-up studies in one patient after subtotal adrenalectomy indicated the persistence of adrenocortical hyperfunction, which was almost completely abolished after total adrenalectomy although a small but definite secretion of cortisol remained. In a second patient there was evidence for the persistence of adrenocortical hyperfunction for several months after total adrenalectomy; the final termination of this state is ascribed to infarction of a small remnant of adrenal tissue.