Cushing's syndrome: analysis of 188 cases.

From January 1962 through April 1988, 188 patients with Cushing's syndrome were hospitalized at the Veterans General Hospital. Iatrogenic Cushing's syndrome was found in 123 (65.4%) of the patients. The other 43 patients (22.9%) had excess secretion of adrenocorticotropin (ACTH) and 22 patients (11.7%) had benign or malignant adrenocortical tumors. The clinical features and the functional reserve of the adrenal glands in those patients with iatrogenic Cushing's syndrome were evaluated. A retrospective analysis of the diagnostic rate of the various endocrine evaluations and the radiological examinations was also carried out. Four approaches were used in the management of Cushing's syndrome: (1) pituitary surgery, (2) pituitary irradiation, (3) adrenal surgery, and (4) drug therapy. Both the clinical and hormonal responses to these four management types were evaluated. The endocrinological, radiological, surgical and pathological experiences of 25 patients with Cushing's disease treated with pituitary surgery are presented. Five patients (20%) had an atypical endocrine pattern (20% false-negative). Twenty-four patients received a pituitary CT scan and 16 patients (66.7%) had positive CT findings. Of these 25 patients, 19 had pathology-proven microadenomas (less than 1cm), one had macroadenoma (greater than 1cm) and 5 had no evidence of adenomatous tissue. Among the 22 patients with adrenal Cushing's syndrome, 4 (18%) were suffering from adrenocortical carcinoma and 18 (82%) with benign adrenal tumors. The incidence of left adrenal adenoma was approximately twice that of right adrenal adenoma. The cure rate of adrenocortical adenoma by surgical treatment with unilateral adrenalectomy was excellent, but for adrenocortical carcinoma was poor.