椎管内神经鞘瘤少见影像表现及误诊分析

MRI Features and Misdiagnosis Analysis of Atypical Spinal Schwannomas

目的探讨椎管内神经鞘瘤少见的影像表现,提高对该病的认识。方法回顾分析经手术病理证实、影像学误诊的29例椎管内神经鞘瘤影像表现。结果髓外硬膜下25例,硬膜内外者3例,硬膜外者1例;C1～S4水平均可见肿瘤发生,多发者5例,肿瘤形态多样。MR T1WI上呈等、低或高信号,T2WI上信号多样,以等或高信号为主;增强扫描以不均匀、明显强化为主。CT像上6例可见骨质破坏。位于胸髓平面以下者主要误诊为室管膜瘤(9例),伴骨质破坏者与骨肿瘤混淆(5例)、多发者主要误诊为神经纤维瘤(3例)和转移瘤(1例),MRI为等信号且增强明显强化的肿瘤主要误诊为血管源性肿瘤(4例)和脊膜瘤(2例),2例误诊为非肿瘤性病变即血肿及游离髓核(各1例)。结论椎管内神经鞘瘤影像表现多样,单发或多发均可,部分可伴骨质破坏,确诊需综合肿瘤部位、信号及强化等特点考虑。

Objective To investigate the imaging features of atypical spinal Schwannomas and to improve the diagnosis. Methods The MR features of 29 cases of spinal Schwannomas confirmed by surgical operation and pathology were retrospectly analyzed. Results 25 lesions located at intradural and extramedullary space , 3 lesions located at intradural and extraduralspace, 1 lesion located at extradural space. The scope of tumors were wide spread from Ct to S4 segments. The shapes of tumors were diversity. The signals of tumors were iso , hypointensity or hyperintensity in T1 WI and iso or relative hyperintensity in T2WI. The tumors were heterogeneous and obvious enhancement on contrast images. At the same time there were 6 lesions showed bone destruction on CT imagings. 9 cases were misdiagnosed as ependymoma mostly located below thoracic level. And 5 eases with bone destructions were misdiagnosed as osteo tumors. Multiple schwannomas were misdiagnosed as neurofibromatosis （NF）（4cases ） and metastasis tumor（ lease ） . The isointensity and obvious enhancement tumors were misdiagnosed as vascular tumors （4 cases） and spinal meningiomas （2 eases）. There were 2 cases misdiagnosed as non-neoplastic lesions including hematoma and free nucleus pulposus. Conclusion The imaging appearances of spinal Schwannomas were variable. Analysis of location, signal and enhancement characters of tumors should help to make accurate diagnosis.