Do tumors ever cause acromegaly or gigantism by making excessive GHRH?
Yes. Rare cases of GHRH production by various tumors have been described in the lung, gastrointestinal tract, or adrenal glands. They cause acromegaly by stimulating pituitary secretion of GH. The clinical and biochemical features of acromegaly are indistinguishable from those of acromegaly caused by a pituitary adenoma. Pituitary enlargement also occurs as a result of hyperplasia of somatotrophs. Some patients have had inadvertent transsphenoidal surgery (TSS) before the correct diagnosis was made. Therefore the plasma level of GHRH should be measured in any patient with acromegaly as well as an extrapituitary abnormality or hyperplasia on pituitary pathology.