BACKGROUND & AIMS:
The authors present their experience of secondary cholesteatomas of the middle ear explored by computerized tomography (CT). Following a brief anatomicopathological description of secondary petrous bone cholesteatomas, and of the CT technique used for their exploration, they describe and illustrate the classical "bag-shaped" internal or external attical forms usually extended to the antrum and the mastoid process, and the less common locations often due to relapse or postoperative recurrences (anterior hypotympanic or posterior mastoidal). The holotympanic forms, usually due to "lamellar" cholesteatomas, create diagnostic problems with other opacities in the cavity, as also do certain forms that are evacuated spontaneously or by aspiration. One of the qualities of CT lies in the preoperative extension assessment. The lesion may extend towards the internal wall of the cavity (lateral semicircular canal, second portion of the facial nerve), towards the labyrinth to the petrosal apex and/or the geniculate ganglion, and above all towards the inferior labyrinth which might bring the cholesteatoma into contact with large vessels (e.g. jugular vein bulb for postero-inferior extensions, carotid canal for antero-inferior extensions). Extension into anfractuosities of the cavity walls (sinus tympani, subratubal fossette) must be systematically looked for in order to avoid postoperative recurrences.
背景与目标:
作者介绍了通过计算机断层扫描 (CT) 探索的中耳继发性胆脂瘤的经验。在对继发性岩骨胆脂瘤以及用于其探索的CT技术进行了简要的解剖学病理学描述之后,他们描述并说明了通常扩展到胃窦和乳突过程的经典 “袋状” 内部或外部形态,较不常见的位置通常是由于复发或术后复发 (前低潮或后乳突)。通常由于 “层状” 胆脂瘤引起的全鼓形式,会在腔内产生其他混浊的诊断问题,以及自发或通过抽吸抽空的某些形式。CT的质量之一在于术前扩展评估。病变可以向腔的内壁 (外侧半规管,面神经的第二部分) 延伸,向迷宫延伸到岩骨尖和/或膝状神经节,最重要的是走向下迷宫,这可能会使胆脂瘤与大血管接触 (例如颈静脉球用于后下方延伸,颈动脉管用于前下方延伸)。为了避免术后复发,必须系统地寻找延伸到腔壁的骨折 (鼓室窦,支气管下窝)。