從海綿竇內內頸動脈(internal carotid artery) 所產生的巨大動脈瘤雖然非常罕見但卻重 要。它可延伸到蝶鞍(sella)，表現出如同腦下垂體腺瘤(pituitary adenoma)引起腦下垂體功能 障礙。我們報告一個因蝶鞍上顱內巨大動脈瘤，導致腦下垂體功能不足和高泌乳素血症的病 例。這名49 歲的婦女以視力逐漸模糊併視野缺損來我們醫院就診，進一步檢查發現腦下垂體 功能低下(pituitary insufficiency)和高泌乳素血症(hyperprolactinemia)。她的腦下垂體磁振掃描 (MRI)和腦血管造影檢查顯示在右側遠端內頸動脈出現不規則囊狀動脈瘤。她接受頸動脈內 透過支架送入線圈實施動脈瘤栓塞手術，以縮小動脈瘤的佔位效應。一年半後追蹤顯示，腦 下垂體的功能部分恢復，泌乳激素(prolactin)血清值降低，視野部分恢復正常。蝶鞍上顱內動 脈瘤常常有類似腦下垂體瘤的外觀和臨床表現，如果沒有被及時的加以診斷及治療，有可能 導致臨床嚴重的後果。

Giant aneurysms originate from the cavernous internal carotid artery (ICA) is a very rare but important condition. It can extend into the sella and simulate pituitary adenomas, sometimes present with pituitary dysfunction. We report a case of pituitary insufficiency and hyperprolactinemia secondary to suprasellar giant intracranial aneurysm. The 49-year-old woman presented at our institution with symptoms of visual field defect, hypopituitarism and hyperprolactinemia were found after investigation. Her pituitary MRI and cerebral angiography revealed a giant irregular saccular aneurysm over right distal internal carotid artery. Transarterial embolization through stent insertion and then coiling was performed on the patient to decrease the mass effect of aneurysm. After treatment, her one and half year follow-up showed decrease of prolactin (PRL) level,partially recovery of pituitary function and visual field. An suprasellar intracranial aneurysm can often simulate the appearance and behavior of a pituitary tumor, potentially resulting in serious outcomes if they are not appropriately recognized.