侵及鼓室、乳突的外耳道胆脂瘤诊断和治疗

目的探讨侵及鼓室、乳突的外耳道胆脂瘤的临床表现、影像特点及其手术治疗方法.方法回顾性分析我科1998～2003年收治的侵及鼓室、乳突的外耳道胆脂瘤14例患者的临床资料.结果14例患者病变均不同程度破坏外耳道四壁并向后扩展至乳突腔.其中4例鼓膜松弛部穿孔,胆脂瘤侵入鼓室,听骨链受压、内移,或不同程度破坏.3例面神经垂直段骨质破坏.1例乳突广泛破坏,硬脑膜裸露.1例先天畸形外耳道狭窄.根据病变的范围,8例行改良乳突根治术,5例行开放式乳突根治术,1例行外耳道扩大成形术.10例听骨链未受累的,术后听力恢复正常,1例听骨链受压变形、移位,术后仍达到正常听力.3例听骨链中断,行听骨链重建术,语言频率气导平均听阈提高15 dB～20 dB.14例患者随访18个月至5年未见复发.结论外耳道胆脂瘤的病因目前尚不十分清楚.侵及鼓室乳突者临床表现不典型,诊断有一定难度,术前常规高分辨颞骨CT扫描,有助于原发部位的判断及确定病变范围,以选择合适的手术方式.

Diagnosis and treatment of the external auditory canal cholesteatoma invading the tympanic cavity and mastoid

OBJECTIVE To discuss the clinic presentation,imaging characteristics and surgical management of the external auditory canal cholesteatoma (EACC) with invasion of the tympaniccavity and the mastoid. METHODS This was a retrospective study including the clinical data of 14 cases of EACC invading tympanic cavity and mastoid from 1998 to 2003 . RESULTS All 14 cases showed different bone erosion in the four walls of external auditory canal with extention to the mastoid . Pars flaccida perforation were found in 4 cases with invasion of the cholesteatoma into the tympanic cavity, the ossicular chains were compressed or destroyed. The bony mastoid segment of facial canal was destroyed in 3 cases . Cerebral plate destruction and congenital stenosis of external auditory canal were found in one case respectively. According to the extent of disease, modified radical mastoidectomy was performed in 8 cases and radical mastoidectomy in 5 cases , meatoplasty in one case. The post-operative hearing of 10 cases with intact ossicula chains were normal.One case with compression,shift of ossicules also got normal audition after the operation. The hearing threshold of the air condition in 3 cases with ossicular disruptions got 15 to 20dB of improvement among the language frequency after reconstruction of ossicular chain. The 14 cases were followed-up from 18 months to 5 years and no recurrences were found. CONCLUSION The exact etiology of EACC still remains unclear. There is some difficulty in diagnosing external auditory canal cholesteatoma (EACC) invading the tympanic cavity and the mastoid because of its untypical clinic presentation . High-resolution temporal bone CT scan could help to find out the primary lesion and determine the range of the pathological changes, and choose the proper surgical approach.