Ectopic GHRH and Acromegaly	

Carcinoid tumours, usually of the pancreas or lung, may rarely be the cause of acromegaly due to ectopic secretion of hypothalamic growth hormone releasing hormone (GHRH). However, instead of a pituitary tumour, these patients have somatotroph hyperplasia in the pituitary, which nevertheless may enlarge the fossa. 

See also:
• Ectopic GHRH Syndrome