Acromegaly.

Subcellular mechanisms support the notion of an intrinsic pituitary defect in acromegaly, with elevated growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels that affect the cardiovascular and respiratory system, as well as neoplastic cell proliferative activity. Surgery, even with external-beam irradiation adjuvant therapy, is only successful in less than 60% of patients, and there are side effects. Normalization of GH levels may improve survival rates. Octreotide has revolutionized patient management, normalizing GH and IGF-1 levels in up to 60%, ameliorating soft-tissue abnormalities and reducing tumor size in up to 50%, and attenuating GH levels in more than 90% of patients. Issues concerning the role of octreotide, as well as clarifying precise outcome measures, still need to be resolved.