自发性颞下颌关节外耳道疝的耳镜、CT及MRI诊断

The spontaneous herniation of temporomandibular joint into external auditory canal ： diagnosis of otoscopy, CT and MRI

目的 总结自发性颞下颌关节外耳道疝的耳镜、CT及MRI表现,提高对该病的认识.方法 回顾性分析3例经手术病理证实为自发性颞下颌关节外耳道疝患者的临床资料,包括耳镜检查和CT、MRI检查所见,总结其特点.结果 3例患者耳镜检查均可见外耳道前下壁软组织肿块,随张、闭口而前后运动.3例患者CT均表现为外耳道骨部前下壁骨质缺损伴软组织肿块,骨缺损区边缘光整,其中2例骨缺损边缘骨壁呈抱球状,部分包绕软组织肿块边缘,2例肿块边缘见薄的不完整假性骨包壳;软组织肿块密度与颞下颌关节软组织密度相同,增强后无显著强化.在MRI所有序列中,外耳道肿块与颞下颌关节囊信号一致,并与之相延续,无强化.结论 自发性颞下颌关节外耳道疝的耳镜、CT及MRI检查均有特征性表现;张、闭口耳镜、CT及MRI检查对该病的诊断具有重要意义.

Objective To summarize the otoscopy,CT and MRI features of spontaneous herniation of the temporomandibular joint（TMJ） into the external auditory canal （EAC） through the persistence Huschke＆#39;s foramen（PHF）.Methods The otoscopy,CT and MRI images of three cases with the herniation of the TMJ into the EAC through the PHF were analyzed retrospectively.Results Otoscopy revealed the masses located in the antero-inferior aspect of the bony EAC,and the mass displayed an alternative of forward and backward motion during opening and closing of the mouth.CT of the temporal bone showed a bony defect and a consecutive soft mass in the antero-inferior wall of the bony EAC.The margin of the bony defects were well-defined in all cases,the bone adjacent to PHF was pressed and partially wrapped around the soft mass as ‘ holding ball’ in two cases,partly peripheral pseudo bony shell of the soft mass were showed in two cases.The soft mass in EAC appeared equal attenuated with the soft tissue of TMJ,and on enhanced CT scans showed no enhancement of the soft mass.On MRI scans,the imaging displayed a bony defect in the antero-inferior wall of the EAC with a soft mass which was formed by the capsule of the TMJ,and the mass showed iso-signal to the capsule of the TMJ on all sequences,and there was no enhancement after contrast administration.Conclusion The otoscopy,CT and MRI features of the spontaneous herniation of the TMJ into the EAC through the PHF is special,and the above examinations are valuable for diagnosis of the disease.