Alorainy Ibrahim A
Department of Radiology and Diagnostic Imaging, King Khalid University Hospital, King Saud University, PO Box: 9047, Riyadh 11413, Saudi Arabia.
Eur J Radiol. 2007 Jun;62(3):378-84. doi: 10.1016/j.ejrad.2007.01.010. Epub 2007 Feb 15.
To document the presence of incidental petrous apex cephalocele (PAC) in association with empty sella in a group of patients and propose an etiologic/pathologic relation between the two lesions.
Retrospective review of our imaging archive for the period from October 2001 to October 2006 revealed five patients with PAC (four females and one male; age range, 25-60 years; mean, 47 years). All patients underwent enhanced MR examination of the skull base and four of them underwent CT examination. Lesions were evaluated for size, content, signal intensity, enhancement, and relation to Meckel's cave and petrous apex. Images were also evaluated for the presence of empty sella.
The presenting symptoms in all patients were not attributable to PAC. None of the patients had symptoms related to the trigeminal nerve or history of CSF leak. Four patients had bilateral PAC and one had left PAC (total nine lesions). The lesions ranged from 6 mm to 15 mm (mean 9 mm) in the maximum diameter. All lesions were centered posterolateral to Meckel's cave and had low attenuation on CT with sharply demarcated margins. No lesion reached the inner ear structures, internal auditory canal, or mastoid air cells. On MR imaging, all lesions demonstrated CSF signal intensity that is continuous with that of the Meckel's cave. Only the periphery of the lesions demonstrated mild enhancement. All patients had empty sella. One patient had small arachnoid cysts in the middle cranial fossa, bilaterally.
PAC and empty sella are similar mechanically in terms of CSF extension and erosion into petrous apex and sella, respectively. Both conditions are seen predominantly in females and have been reported in association with CSF leak, which raises a possibility of etiologic/pathologic relation between the two.
记录一组患者中偶然发现的岩尖脑膨出（PAC）与空蝶鞍并存的情况，并提出这两种病变之间的病因/病理关系。
回顾性分析2001年10月至2006年10月期间的影像存档资料，发现5例PAC患者（4例女性，1例男性；年龄范围25 - 60岁，平均47岁）。所有患者均接受了颅底增强磁共振检查，其中4例还接受了CT检查。对病变的大小、内容物、信号强度、强化情况以及与Meckel腔和岩尖的关系进行评估。同时评估影像上是否存在空蝶鞍。
所有患者的首发症状均与PAC无关。无一例患者有与三叉神经相关的症状或脑脊液漏病史。4例患者为双侧PAC，1例为左侧PAC（共9个病变）。病变最大直径为6 mm至15 mm（平均9 mm）。所有病变均位于Meckel腔后外侧，CT上呈低密度，边界清晰。无病变累及内耳结构、内耳道或乳突气房。在磁共振成像上，所有病变均表现为与Meckel腔连续的脑脊液信号强度。仅病变周边有轻度强化。所有患者均有空蝶鞍。1例患者双侧中颅窝有小的蛛网膜囊肿。
PAC和空蝶鞍在脑脊液分别向岩尖和蝶鞍延伸及侵蚀方面，在机械原理上相似。这两种情况均多见于女性，且均有与脑脊液漏相关的报道，这提示两者之间可能存在病因/病理关系。
