[The diagnosis of Cushing's syndrome. Results of diagnostic assessment of 20 patients with Cushing's syndrome of variable etiology (1979-1989)].

In the light of 20 cases of Cushing's syndrome the currently used diagnostic strategies are presented. For initial screening the classical dexamethasone suppression test using 1 mg dexamethasone p.o. and 24-hour urinary extraction of free cortisol were used, and diagnosis was confirmed using the 2 mg dexamethasone suppression test for two days. All three tests had a sensitivity of 100% in these 20 patients. Etiological evaluation was performed using basal ACTH plasma concentration measurement and the more recently available stimulation tests using corticotropin-releasing factor (CRF): in cases with suspected pituitary-hypothalamic etiology, selective catheterisation of the sinus petrous inferior with simultaneous blood sampling for measurement of plasma ACTH concentration was performed. Detailed etiological diagnosis is important in Cushing's syndrome since therapeutic measures differ widely: the etiologies in the 20 patients with Cushing's syndrome were: central Cushing's disease (microadenoma in 11, pituitary carcinoma in 1), adrenal carcinoma (3), adrenal adenoma (1), adrenal hyperplasia (1), ectopic ACTH production (2) and alcohol-induced Cushing's syndrome (1). The stepwise procedure in screening and diagnosis of the various etiologies of Cushing's syndrome are presented and the results of the 20 patients compared with the literature.