乳头状内淋巴囊瘤的影像学表现

目的 探讨乳头状内淋巴囊瘤的CT、MRI和DSA特征。方法 回顾性分析总结5例组织病理学证实的乳头状内淋巴囊瘤的CT骨破坏特点及MRI信号特征、强化方式、血液流空情况，4例同时进行DSA检查，以观察血供状态。CT采用常规横轴面平扫和增强扫描；MRI采用SE和快速自旋回波（FSE）及脂肪抑制序列，行矢状、冠状和横轴面平扫和增强扫描。结果 （1）CT表现：肿瘤呈中心位于颞骨岩部迷路后区的溶蚀性骨破坏，病变内含钙化。（2）MRI表现：在未增强T1WI和T2WI，5例肿瘤内见不规则形低信号影，其中心位于颞骨岩部中后部的前庭管外口周围区；3例肿瘤周边显示高信号缘；2例囊实性肿瘤的囊性部分呈高信号，脂肪抑制像高信号不被抑制，而且其边缘更清楚；5例瘤内均见血管流空影。（3）DSA显示肿瘤主要由颈外动脉的分支供血。其中2例还有小脑前下动脉参与供血。结论 乳头状内淋巴囊瘤是位于颞骨岩部迷路后区的具有侵袭性、溶骨性、富含血管的肿瘤，它的影像学特征结合发生部位有助于诊断及鉴别诊断。

Imaging appearance in papillary endolymphatic sac tumors

Objective To evaluate the imaging findings on CT, MRI, and angiographyin patients with papillary endolymphatic sac tumors (PELSTs). Methods CT and MR imaging studies in 5 patients (aged 12- 41 years) with histopathologically proved papillary endolymphatic sac tumors were retrospectively reviewed, and four of the five also underwent angiograms. CT scans were evaluated for bone erosion and calcification, MR images for signal intensity changes, enhancement patterns, and flow voids, and angiograms for tumor blood supply . Results All tumors were destructive, containing calcifications centered in the retrolabyrinthine region and showing irregular bone margins on CT. MR imaging appearance varied with lesion size and nature. Three of the five tumors showed a high signal intensity margin on unenhanced T 1 and T 2 weighted images, and the margins were more clear with fat suppress imaging. The others were heterogeneous and contained cystic high signal intensity area on both T 1 and T 2 weighted images. All the tumors showed irregular low signal intensity within the endolymphatic sac anatomicallyand flow voids signals. The blood supply arose predominantly from the external carotid artery. Two tumors had additional supply from posterior circulation. Conclusion Papillary endolymphatic sac tumors are destructive and hypervascular lesions that arise from the retrolabyrinthine region in the temporal bone. These imaging findings combined with the original location may help distinguish PELSTs from other more common and aggressive temporal bone tumors.