单椎体孤立性浆细胞瘤的CT及MRI特征与病理分析

CT and MRI features and pathological analysis of solitary plasmacytoma of spine

目的分析单椎体孤立性浆细胞瘤(solitary plasmacytoma of spine,SPS)患者的CT及MRI特征与病理机制,以提高对SPS的认识及诊断水平,为治疗提供帮助。方法回顾性分析17例经手术和病理证实SPS患者的CT及MRI资料与病理结果。17例均行MRI及增强检查,其中10例同时行CT检查。分析17例患者的CT及MRI表现及相关病理特征。结果肿瘤可以累及脊柱各节段,以胸椎及腰椎多见。17例SPS均表现椎体不同程度溶骨性骨质破坏,轻度膨胀性改变,累及附件14例,椎体压缩楔变13例;椎体边缘形成不对称软组织肿块13例,软组织肿块突入椎管内12例,包绕椎管形成“围管征”7例;CT可见破坏区局部边缘骨质轻微硬化4例,病灶内可见较为粗大的骨嵴8例;T1WI序列呈等、低信号,T2WI序列多呈等或略高信号;增强扫描均明显均匀强化,14例表现为“微脑样”征像。病理组织学特征:肿瘤细胞由弥漫性密集排列的小圆细胞组成,几乎没有细胞间基质。免疫表型:17例均表达CD138及CD38,12例表达Kap,7例表达Lambda,11例表达CD79a,仅2例表达CD20。结论SPS的CT及MRI表现具有一定的特征性,了解其CT及MRI特征与相关病理机制有助于与其他单发脊柱肿瘤鉴别,可提高术前诊断准确性。

Objective To analyze the computed tomography(CT)and magnetic resonance imaging(MRI)features and pathological mechanism of patients with solitary plasmacytoma of spine(SPS),thus enhancing the understanding and diagnostic capacity of SPS for a better clinical treatment.Methods CT and MRI data and pathological results of 17 patients with SPS confirmed by surgery and pathology were retrospectively analyzed.MRI and enhanced MRI were performed in all the 17 cases,including 10 cases additionally examined by CT.The CT and MRI findings and related pathological features of 17 patients were analyzed.Results SPS involved all segments of the spine,especially thoracic vertebra and lumbar vertebra.All involved 17 SPS patients presented varying degrees of osteolytic bone destruction,and mild swelling changes Accessories and vertebral compression wedge were seen in 14 and 13 cases,respectively.Asymmetric soft tissue masses formed in the vertebral edge,soft tissue masses protruding into the spinal canal,and a“encircling sign”surrounding the spinal canal was observed in 13,12 and 7 cases,respectively.CT scans showed slight bone sclerosis at the local edge of the damaged area,and relatively thick bone crest in 4 and 8 cases,respectively.Tumor lesions of SPS mostly showed an isointensity or slightly hypointensity on the T1 weighed images(T1WI),and an isointensity or slightly hyperintensity on the T2 weighed images(T2WI).Obvious enhancement was detected in all cases.The microencephalic sign Was detected in 14 cases.Histopathological features of SPS included small,densely packed round neoplastic cells,and barely expressed matrixes.Detection of the immunophenotype showed positive expressions of CD138 and CD38 in 17 cases,positive expression of Kap in 12 cases,positive expression of Lambda in 7 cases,positive expression of CD79a in 11 cases and positive expression of CD20 in only 2 cases.Conclusion The CT and MRI features of SPS have certain characteristics.Understanding the CT and MRI features and pathological mechanism of SPS are helpful to differentiate it from other single spinal tumors and improve the accuracy of preoperative diagnosis.