Letter: Growth hormone after transsphenoidal hypophysectomy.

To the Editor.— The role of hypophysectomy in the management of metastatic female breast cancer is well established. Although complete removal of the pituitary gland is not necessary to achieve a remission, there is evidence for a correlation between the extent of pituitary ablation and the rate and duration of remission and also of survival. This correlation has been well documented in hypophysectomy for prostatic cancer, after comparing the results of open hypophysectomy to those of cryohypophysectomy. 1 Cryoblation frequently effects a less-complete anatomical and endocrinological destruction of the pituitary gland than the classic frontal craniotomy and hypophysectomy under direct vision. 2 The recently revived extracranial transsphenoidal approach, under direct magnified visualization of the gland with the dissecting microscope, offers many appealing advantages over the craniotomy. 3 Growth-hormone release after controlled provocation has been suggested as the most reliable test for evaluation of the completeness of hypophysectomy. We have used