Serial plasma growth hormone concentration during selective removal of pituitary tumors in acromegaly.

Abstract

✓ The pituitary function of two patients with acromegaly was monitored before, during, and after selective transnasal pituitary adenomectomy. The purpose of the study was to verify the efficacy of this technique, and to see if there was normal function in the residual pituitary tissue. Following surgery, both patients showed clinical improvement with no evidence of significant anterior or posterior pituitary dysfunction. Concentrations of plasma growth hormone obtained serially during surgery were elevated prior to tumor removal but fell precipitously after adenomectomy. The half-life for immunoreactive growth hormone in these patients was less than 35 minutes. We conclude that selective transnasal pituitary adenomectomy is an effective treatment for pituitary tumors. Furthermore, our data suggest that the pituitary tumor in these patients did not arise because of excessive stimulation by hypothalamic growth hormone-releasing factor.