内淋巴囊肿瘤的影像学表现及鉴别诊断

Imaging Findings of Endolymphatic Sac Tumors and its Differential Diagnosis

目的:探讨内淋巴囊肿瘤的影像学表现、诊断及鉴别诊断要点,提高对该罕见肿瘤的认识。方法:回顾性分析5例经组织病理学证实的内淋巴囊肿瘤的CT平扫、MRI平扫+增强图像,并复习相关文献,总结其影像学表现及鉴别诊断要点。结果:内淋巴囊肿瘤呈中心位于颞骨岩部中后缘(即内淋巴囊解剖部位所在)血供丰富的浅分叶状软组织肿块,伴邻近骨质"蜂窝状"溶骨性破坏。CT表现:肿块内部见较多细针状高密度骨样结构,后缘见不规则薄层钙化缘。MRI表现:肿块T1WI、T2WI均呈混杂信号,边缘见短T1、长T2高信号影,较大肿瘤伴血管流空征,动态增强曲线呈速升缓降型。结论:内淋巴囊肿瘤的影像学表现具有一定的特征性,结合其发生部位有助于临床诊断及鉴别诊断。

Purpose： To describe the imaging findings, diagnosis and differential diagnosis of endolymphatic sac tumors （ELST）, and to improve the understanding of this rare tumor. Methods： The CT and enhanced MR imaging findings of 5 patients with histopathologically proved endolymphatic sac tumors were retrospectively anlyzed, and the related literatures were reviewed, and then the key points of the imaging diagnosis were summed up. Results： ELST aroused from the anatomical structure of endolymphatic sac in the petrosal region of temporal bone, which was hypervascular and bulged destructive disease eroding surrounding bone structure. Spicules intratumoral bone and peripheral calcifications were shown on CT. The tumors were with heterogeneous signal intensity on MRI, and hyper- intensity signal was shown in the peripheral region. Flow voids signals could be seen in large tumors. The dynamic enhanced curve showed rapid enhancement and slow washout. Conclusion： Imaging findings of ELST have some characteristics, combined them with the location are helpful for its diagnosis and differential diagnosis.