Cushing's disease: a correlation of radiological, surgical and pathological findings with therapeutic results

From 1963 to 1990 78 successive patients with pituitary-dependent cortisol hypersecretion were submitted to transsphenoidal surgery. In 57 patients, a selective adenomectomy was performed. Sixteen other patients had a central hypophysectomy. Total hypophysectomy was done nine times: in five new patients and in four patients previously operated by us. Fifty-six tumors were studied in pathology. Fifty tumors were microadenomas with ten of these measuring less than 1 mm. The tumors consisted of basophilic cells giving a positive immunostaining for ACTH. Electron microscopy on 35 tumors was characteristic with perinuclear bundles of microfilaments and often large lipid vacuoles. We did not find ACTH cell hyperplasia in the pituitary gland around tumors or in specimens of central or total hypophysectomy. Adequate follow-up was obtained on 49 patients who had been cured with an average length of 6.4 years after surgery. Our longest sustained remission following selective adenomectomy is eighteen years. Surgical cure rate was 82% for microadenomas and 81% for all intrasellar tumors. 89% of patients went into remission after total hypophysectomy but only 56% when central hypophysectomy was performed. Recurrence rate was 7.6%, occurring between three and seven years after surgery.