Surgical remission of pituitary adenomas confined to the neurohypophysis in Cushing's disease.

CONTEXT

Partial or total removal of the pituitary cures 60-80% of patients with Cushing's disease (CD) in whom an adenoma cannot be identified at surgery. Many patients who fail complete or partial hypophysectomy are cured by sellar and parasellar irradiation.

DESIGN/PATIENTS: As part of a series of prospective studies of CD, we identified 12 patients (34.5 +/- 19.9 yr; 11 females; four children) with tumors located completely within the neurohypophysis among 730 patients undergoing surgery for CD.

SETTING

The study was conducted at a tertiary referral center at a clinical research hospital.

RESULTS

All 12 patients had clinical and biochemically defined CD. Tumor was visible at surgery in 11 patients; all 12 tumors were positive for ACTH by immunohistochemistry. Two tumors were excised at repeat surgery because of persistent hypercortisolism within 14 d of negative exploration of the adenohypophysis. There were no long-term complications. At follow-up of 71.9 +/- 34.2 months (range, 30-138 months), all patients are in remission of CD. Adult patients have had significant improvement in weight and body mass indices, with restoration of normal menses in all women. In the four pediatric patients, height, weight, and body mass indices have been restored toward normal by surgical remission of CD. Hypopituitarism or long-term neurohypophysial dysfunction has not occurred.

CONCLUSION

We report a new subset of patients with CD, ACTH-secreting adenomas that arise wholly within the posterior lobe of the pituitary gland. In cases of CD in which an adenoma is not identified in the adenohypophysis and in patients with persistent hypercortisolism after complete or partial excision of the anterior lobe, tumor within the neurohypophysis should be considered; selective adenomectomy of a neurohypophyseal, ACTH-secreting tumor can produce long-term remission.