內聽道內蜘蛛膜囊腫－病例報告

Arachnoid Cyst in the Internal Auditory Canal – Case Peport

邱康瑄(Kang-Hsuan Chiu) ； 林凱南(Kai-Nan Lin)

《中華民國耳鼻喉科醫學雜誌》 34卷1期 (1999/01) Pp. 52-55

https://doi.org/10.6286/1999.34.1.52

摘要

內聽道內的腫瘤以聽神經瘤最多。其他較不常見的病變如腦膜瘤、脂肪瘤及蜘蛛膜囊腫等，在診斷上必須和聽神經瘤加以區分。蜘蛛膜囊腫在病因學上是由於蜘蛛膜分裂或重複造成腦脊髓液積蓄其間所造成。本部在1997年8月間經歷一名25歲的女性病人，主訴右側偏頭痛、耳嗚、漸近性聽力損失及頭暈。純音聽力檢查顯示右側感音性重聽，腦幹聽性反應檢查懷疑有耳蝸後病變，電腦斷層掃描發現右側內聽道擴大，而核磁造影檢查則發現右側內聽道內有T2影像為高訊號且T1下不被顯影劑加強的腫瘤存在。以經迷路方式打開內聽道，結果發現一內含腦脊髓液之囊腫而其中的神經受到壓迫而呈扁平萎縮狀。病人術後曾有智暫的頭暈及顏面神經麻痺的現象，但都在半年內逐漸恢復。

關鍵字

蜘蛛膜囊腫 ； 內聽道

並列摘要

Acoustic neuroma is the most frequently encountered tumor in the internal auditory canal (IAC). Other lesion, such as meningioma, lipoma and arachnoid cyst, are rarely seen in the IAC. Differentiation among these tumors is difficult because of the presence of similar clinical pictures and audiological findings. In this paper, a case of IAC arachnoid cyst is reported, emphasizing the imperative value of magnetic resonance imaging (MRI) studies in diagnosis. The patient was a 25-year-old woman who had experienced right hemicrania, dizziness, progressive right hearing impairment, and tinnitus for 2 years before presenting at our clinic. An imaging study of the IAC MRI revealed a highintensity signal in the T2WI though there was no Gd-DTPA enhancement in the T1WI. A translabyrinthine approach was used to remove the cyst. Compression of the nerves was found in the IAC. In the postoperative period, the patient experienced short-lived facial weakness and dizziness that resolved completely within 6 months. We believed that MRI studies can provide information in the differential diagnosis of IAC lesions.

並列關鍵字

arachnoid cyst ； internal auditory canal