Pre-operative treatment of 5 acromegalics with a somatostatin analogue: endocrine and clinical observations.

Five acromegalic patients were treated preoperatively over a period of 1-4 weeks with the somatostatin analogue SMS 201-995. The patients received daily 3 X 100 micrograms of SMS 201-995 subcutaneously. This schedule resulted in a rapid improvement of the clinical symptoms in 4 out of 5 patients. In these same patients plasma growth hormone concentrations decreased markedly. However, only in one patient were growth hormone concentrations normalized. Plasma IGF I, which was elevated in all patients, was normalized only in this same patient. Tumour volume as determined by thin section CT-scans decreased only in one case by 17%. All tumours appeared extraordinarily soft upon operation. Conventional light microscopy showed no difference between tumours of SMS-pre-treated and untreated patients. Ultrastructural investigation showed the usual heterogeneity.