脊柱恶性外周神经鞘瘤的CT和MRI表现

CT and MR Manifestations of Malignant Peripheral Nerve Sheath Tumor in Spine

目的分析脊柱恶性外周神经鞘瘤(malignant peripheral nerve sheath tumor,MPNST)的CT和MRI表现,提高术前对该病诊断的准确性。资料与方法回顾性分析12例经病理证实的脊柱MPNST的CT(n=10)和/或MRI(n=11)表现。结果 MPNST表现为类圆形(n=2)或不规则分叶状(n=10)肿块。3例未见明显骨质破坏,9例有邻近椎骨侵犯,主要侵犯神经孔相邻的椎弓根、椎板及相邻局部椎体,骨质破坏以溶骨性骨质破坏(n=8)为主,少数(n=1)为溶骨性骨质破坏与不规则瘤骨同时存在。CT平扫肿块呈等密度(n=4),等、低混杂密度(n=4)或等、高混杂密度(n=2)。MR T2WI和T1WI上均呈以长T2、长T1为主的混杂信号,内部可见片状T2WI高信号(n=8)或点、条状低信号(n=2)或簇状血管影(n=1)。增强扫描肿块多表现为不均匀强化,内部可见不强化坏死区。10例可见神经孔增宽;9例可见肿块与脊神经相连。结论 CT或MRI像上出现神经孔扩大、周围明显骨质破坏、增强扫描不均匀强化、内部有无强化坏死区的脊柱占位性病变,特别是肿块与脊神经相连时应考虑脊柱MPNST可能。

Objective To explore the CT and MRI manifestations of malignant peripheral nerve sheath tumor（MPNST） located in spine and to improve the preoperative diagnostic accuracy.Materials and Methods The CT（n=10） and/or MRI（n=11） data of 12 cases of MPNST proved by pathological results were analyzed retrospectively.Results MPNST manifested as circular（n=2） or irregularly lobulated tumors（n=10）.Three cases showed inconspicuous bone destruction and 9 cases showed adjacent vertebrae invasion,in which mainly invaded the pedicle of vertebral arch and vertebral laminae adjacent to the neural foramens as well as vertebral bodies adjacent to tumors.The bone destruction was mainly osteolytic destruction（n=8）.Coexistence of osteolytic destruction and irregular tumor bone were seen in one case.The tumors were isodensity（n=4）,coexistence of iso/hypo-density（n=4）,or iso/hyper-density（n=2） on plain CT imaging.The tumors appeared as hyper-intensity on T2WI and hypo-intensity on T1WI.There were patchy hyper intensity areas（n=8）,punctual/stripy hypo-intensity areas（n=2）,clustered vessel signals（n=1） in tumors on T2WI.Inhomogeneous enhancement was seen on contrast-enhanced scan in all the cases.Conclusion The imaging features of tumors included enlarged neural foramens,obvious peripheral bone destruction,inhomogeneous enhancement with non enhanced necrotic area,especially connected with spinal nerve,will help to make a diagnosis of malignant peripheral nerve sheath tumor.