In the vast majority of cases (over 95%), the hypersecretion of growth hormone causing acromegaly is related to the development of a benign pituitary tumor (pituitary adenoma), a small gland (about the size of a chickpea), located at the bottom of the brain, about the height of the nose.

This tumor most often occurs unexpectedly: it is then qualified as “sporadic”. In other, much rarer cases, acromegaly is linked to a genetic anomaly: there are then other cases in the family and it can be associated with other pathologies.

Nevertheless, the opposition between sporadic and familial forms is more and more difficult to maintain, insofar as, in the sporadic forms (without other cases in the family), it has recently been possible to show that there are also genetic mutations. at the origin of the disease.