Acromegaly Due to Secretion of Growth Hormone by an Ectopic Pancreatic Islet-Cell Tumor

THE clinical features of acromegaly result directly or indirectly from sustained hypersecretion of growth hormone.1 2 3 Somatotroph-cell adenomas, or in rare cases hyperplasia, constitute the pathologic pituitary lesions causing acromegaly.4 , 5 Also in rare cases, acromegaly may be caused by ectopic somatotroph-cell adenomas in the sphenoid or parapharyngeal sinuses.4 , 5 Attention has recently been focused on the elaboration of growth hormone–releasing factors by carcinoid6 and pancreatic islet-cell tumors7 causing acromegaly. The structure of human growth hormone–releasing factor was, in fact, first elucidated from two such pancreatic tumor extracts, which were shown to stimulate growth hormone release both in vitro and in vivo.8 , 9 Ectopic . . .