脊柱外周性原始神经外胚层肿瘤的影像学表现与病理学对照分析

目的 分析脊柱外周性原始神经外胚层肿瘤(pPNET)CT及MR表现与病理学特征。 方法 对16例经病理证实的脊柱pPNET患者进行CT平扫(n=16)及CT平扫+增强扫描(n=12)、MR平扫(n=14)及MR平扫+增强扫描(n=9),分析其CT、MRI及病理学特点。 结果 病变位于颈段7例,颈胸段1例,胸段1例,腰骶段6例,多发1例;其中累及椎体1例,椎体及附件10例,椎管内2例,椎旁3例。病灶均呈浸润性生长;5例椎体出现病理性压缩骨折,5例肿瘤内见钙化,无椎间盘受累、骨膜反应及瘤骨形成;CT表现为成骨性、溶骨性及混合性骨质破坏(以溶骨性破坏为主)伴周围较大实体软组织肿块样改变;MR平扫表现为混杂T1WI、T2WI信号,增强扫描中病变不均匀强化,软组织内有囊变坏死区,血供丰富。免疫组化结果提示pPNET均出现CD99特征性膜表达以及不同程度的神经性标记物NSE、Syn、CgA表达。 结论 脊柱pPNET影像表现具有一定特点。CT及MR能显示肿瘤大小、内部结构、范围毗邻,有助于鉴别诊断;最终诊断依赖于病理学检查。

Imaging findings and pathological analysis of spinal peripheral primitive neuroectodermal tumor

Objective To analyze the imaging findings and pathological features of peripheral primitive neuroectodermal tumor (pPNET) of spinal column. Methods Sixteen patients of spinal pPNET underwent imaging examination, including plain (n=16) and contrast enhanced CT (n=12), as well as plain (n=14) and contrast enhanced MRI (n=9). The imaging and pathological characteristics of pPNET were analyzed retrospectively. Results The lesions located in cervical (n=7), cervicothoracic (n=1), thoracic (n=1) or lumbosacral spine (n=6), while lesions of one patient located in multiple spines. Vertebral body (n=1), vertebral body and appendix (n=10), intraspine (n=2) and paravertabral tissues (n=3) were involved. All the lesions manifested infiltration, while pathological compression fractures and internal calcification were detected in 5 patients, respectively. No disk involvement, periosteum reaction nor tumor bone was displayed. CT showed osteolytic, osteoblastic and mixed bone destruction with surrounding soft tissue masses. MR displayed mixed signals on T1WI and T2WI, which enhanced asymmetrically, meanwhile, necrosis, cystic degeneration areas and rich blood supply of soft tissue masses were found. Immunohistochemistry showed distinctive expression of CD99 and expression of other neuroendocrine markers, such as NSE, Syn and CgA. Conclusion Spinal pPNET has some imaging characteristics. CT and MRI can show the size, internal structure, extent and adjacent structure of the tumors, therefore they are being helpful to the differentiating diagnosis, but the final diagnosis still depends on pathological examination.