Etiology of pituitary acromegaly.

Pituitary tumors secreting growth hormone are clonal neoplasms that may arise following a somatic mutation within the somatotroph cell. Promotion of tumor growth also appears to be regulated by hypothalamic growth hormone-releasing hormone, which exerts a trophic action on the pituitary cell. Unraveling the mechanisms of pituitary tumorigenesis will facilitate the application of novel therapeutic techniques, genetic screening, and follow-up of tumor responses.