先天性外耳道狹併發膽脂瘤及耳後膿瘍

Congenital External Auditory Canal Stenosis Complicated with Cholesteatoma and Retroauriclar Abscess

傅子懿(Tzu-Yu Fu) ； 林鴻清(Hung-Ching Lin) ； 陳昱君(Yu-Chun Chen) ； 徐銘燦(Min-Tsan Shu)

《台灣耳鼻喉頭頸外科雜誌》 43卷1期 (2008/02) Pp. 18-22

https://doi.org/10.6286/2008.43.1.18

摘要

先天性外耳道狹窄常合併小耳症、聽小骨異常。除了造成傳音性聽障外，狹窄的外耳道也容易併發膽脂瘤，進而發炎引起膿瘍。高解析電腦斷層攝影檢查，有助於膽脂瘤的診斷、發展及其耳後膿瘍之鑑別診斷。病例1是名8歲男生，兩側小耳症，左側外耳道狹窄併發外耳道膽脂瘤，耳後有膿瘍經排膿後留下的傷口。右耳外耳道完全閉鎖。純音聽力檢查，兩耳爲傳音性聽力障礙，左耳爲47 dB、右耳爲48 dB。左、右耳分別有47 dB、48 dB的氣導骨導差距。高解析電腦斷層攝影顯示左耳外耳道充滿軟組織。患者接受耳道成形術(canalplasty)，手術後純音聽力檢查左耳聽力30 dB。病例2爲5歲男生，左耳正常，右耳爲第2級小耳症合併外耳道狹窄併發耳後膿瘍。純音聽力檢查左耳聽力10 dB爲正常，右耳爲傳音性聽障70 dB，有58 dB的氣導骨導差距。高解析電腦斷層攝影顯示右側外耳道及乳突腔充滿軟組織，診斷爲右側小耳症合併外耳道狹窄併發外耳道膽脂瘤及耳後膿瘍。膿瘍經抗生素及切開引流治療無效後，採手術治療，將外耳道狹窄處內側皮膚連同膽脂瘤及病變組織一起清除，經半年觀察，沒再出現發炎腫痛的情形。

關鍵字

小耳症 ； 外耳道狹窄 ； 膽脂瘤 ； 耳道成形術

並列摘要

The external auditory canal is derived from the first brachial cleft. Congenital canal atresia occurs when the genesis of the external auditory canal (EAC) is interrupted during the embryo stage. EAC stenosis can cause conductive hearing loss; furthermore there is very often external auditory canal cholesteatoma and occasionally retroaucular abscess. EAC cholesteatoma is asymptomatic initially until it manifests as an infection. High resolution computer tomography is a good tool when detecting EAC cholesteatoma. Case 1 was an eight-year-old boy with bilateral microtia. The left ear was noted to have EAC stenosis, EAC cholesteatoma and a wound scar behind the ear due to abscess formation. The right EAC was completely atresia. A pure tone audiogram revealed bilateral conductive hearing loss. The hearing level was 48 dB in the right ear and 47 dB in the left averaged over 500 Hz, 1k Hz and 2k Hz. A high resolution CT scan showed that the left EAC was filled with soft tissue. The EAC cholesteatoma was removed surgically and the patient's hearing was improved specifically the PTA of left ear 30 dB HL a three months follow-up. Case 2 was a five-year-old boy with a right retroauricular abscess that did not improve after antibiotics treatment. His right ear was microtic and had EAC stenosis. A high resolution CT scan showed that the right EAC and mastoid cavity were filled with soft tissue. The PTA revealed a conductive hearing loss with air-bone gap of 58 dB in the right ear and normal hearing in the left. The diagnosis was right EAC stenosis with cholesteatoma formation, which had induced retroauriclar abscess. The cholesteatoma together with the granulation and the epithelium of the stenotic ring were removed. There has been no recurrence of the infection after half year follow-up.

並列關鍵字

microtia ； external auditory canal stenosis ； cholesteatoma ； canalplasty