Alteration of the collagen type III/type I ratio and intracranial saccular aneurysms in GH-secreting hypophyseal adenomas.

In reporting a case of GH-secreting hypophyseal adenoma associated with a carotid-ophthalmic aneurysm we discuss the possible relevance of an alteration of the type III to type I ratio in arterial wall collagen to the formation of intracranial aneurysms, known to be multifactorial in mechanism. The increased turnover of collagen and the type III collagen deficiency in the vessel wall present in acromegaly suggest that this secondary connective tissue change may have a role in the formation of intracranial aneurysms in patients with GH-secreting hypophyseal adenoma.