CT鉴别腹膜后良、恶性神经鞘瘤的诊断价值及其病理基础

CT Diagnosis and Differential Diagnosis of Retroperitoneal Benign and Malignant Neurolemmoma

目的分析腹膜后良性和恶性神经鞘瘤的影像学表现及其与病理的关系,探讨CT对其的诊断和鉴别诊断价值。资料与方法经手术病理证实的腹膜后良性和恶性神经鞘瘤26例,术前分别经螺旋CT或多层螺旋CT平扫和增强扫描,注射流率采用3ml/s。仔细复习CT扫描结果并和手术病理作回顾性对照分析。结果 26例中,良性19例,恶性7例。良性肿瘤直径3.0～15.5cm,平均7.2cm;恶性肿瘤直径4.5～17.0cm,平均7.4cm。19例良性肿瘤边缘光整,境界清楚,邻近脂肪间隙内无异常影。7例恶性神经鞘瘤中,晕样改变5例,毛刺3例,1例既出现毛刺又出现晕样改变;良性神经鞘瘤囊性4例,囊实性9例,实性6例。恶性神经鞘瘤囊性1例,囊实性5例,实质性1例。12例良性神经鞘瘤具有两种不同密度的实质成分(细胞密集区和稀疏区);5例恶性神经鞘瘤依稀可以辨认两种不同密度的实质成分。细胞稀疏区和密集区强化程度不同。靶征可分别见于良性和恶性神经鞘瘤。结论腹膜后良性和恶性神经鞘瘤具有不同密度的实质成分,CT表现取决于细胞稀疏区与密集区的比例和排列方式。良性和恶性神经鞘瘤既有相似之处又存在许多不同之处,但恶性神经鞘瘤大多为分化很差的梭形细胞肉瘤,境界很不清楚(毛刺和晕征),形态不规则,坏死常见,多数良性和恶性神经鞘瘤可以鉴别。

Objective To explore the CT findings of benign and malignant retroperitoneal neurolemmoma and to evaluate it＇s diagnostic and differential diagnostic efficiency.Materials and Methods 26 cases with retroperitoneal benign and malignant neurolemmoma confirmed by surgical pathology underwent CT plain scanning and enhanced scanning before operation.The CT data was reviewed and compared with surgical and pathological results retrospectively.Results The mean tumor diameter of 19 benign neurolemmoma was 7.2 cm（range 3.0 to 15.5 cm）,the mean tumor diameter of 7 malignant neurolemmoma was 7.4 cm（range 4.5 to 17 cm）.Of 19 benign lesions with smooth,regular margins,4 lesions were cystic tumors,6 were solid tumors,9 were mixed tumors.Of 7 malignant lesions,CT showed spiculate border in 3 lesions,halo margin in 5,cystic tumor in 1,solid mixed with cystic tumor in 5,solid tumor in 1lesion.Both benign and malignant neurolemmoma had the component of hypocellularity and hypercellularity.Target sign was showed in either benign or malignant neurolemmoma.Conclusion The CT findings of benign and malignant retroperitoneal neurolemmoma were determined by the proportion and the arrangement of hypocellularity and hypercellularity in the tumor.The benign and malignant retroperitoneal neurolemmoma have some overlap in CT findings.