Pituitary surgery for Cushing's disease.

In this article, the present status of neurosurgical operations for Cushing's disease is briefly reviewed. Transsphenoidal surgery is considered the treatment of choice in most patients with Cushing's disease once the diagnosis has been established. In a considerable proportion of patients, even sophisticated imaging does not directly depict the tiny microadenoma. The search for the tumor is technically difficult, particularly when the sella turcica is small, the dura vascularized and the sphenoid sinus poorly pneumatized. Thus, even in expert hands, microadenomas cannot always be identified intraoperatively. Usually, a selective adenomectomy is attempted, preserving pituitary functions. There is a huge variation of surgical outcomes reported. As an estimate, a remission rate of some 75% can be expected 5 years after surgery. Almost all data available to date derive from microsurgical operations. Unfortunately, even in patients who initially remit, recurrences may occur. Low postoperative serum cortisol levels and a long-lasting adrenocortical insufficiency seem to be factors associated with a favorable long-term outcome. When no distinct microadenoma can be identified intraoperatively, partial or even total hypophysectomy has been suggested. However, the outcome of these procedures is less favorable than with selective resections of distinct adenomas. Less than 10% of pituitary adenomas associated with Cushing's disease are macroadenomas. These also bear a less favorable outcome than microadenomas. Only for selected patients with mainly extrasellar tumor localizations are craniotomies recommended. A close cooperation with the endocrinologist is mandatory for a neurosurgeon operating on patients with Cushing's disease, namely for the pre- and perioperative care and for long-term follow-up.