腹膜后间隙神经鞘瘤的320排CT征象及病理基础

Retroperitoneal Schwannoma: 320-Slice CT Features and Pathology Features

目的分析腹膜后间隙神经鞘瘤的320排CT表现及与病理的关系,探讨320排CT对其诊断和鉴别诊断价值。方法回顾性分析22例经手术病理证实的腹膜后间隙神经鞘瘤的320排CT表现及病理结果。术前均行320排CT平扫与三期增强检查。结果 (1)22例中,良性神经鞘瘤19例,恶性神经鞘瘤3例,盆部腹膜外间隙3例,腹腔腹膜后间隙19例。(2)CT表现,完全囊变型7例,囊实性型12例,完全实性型3例;良性肿块边缘光整,境界清楚,恶性肿块局部边界模糊;所有肿块实性部分呈渐进性延迟轻中度强化,平扫、增强动脉期、门静脉期、延迟期CT值分别(35.40±7.70)HU、(45.09±8.71)HU、(56.27±10.33)HU、(68.64±12.68)HU;术前定位准确度100%,定性准确度90.90%(20/22)。(3)病理表现,镜下,肿瘤内可见Antoni A区和Antoni B区两种组织类型,Antoni A区细胞密集排列,Antoni B区细胞稀少,细胞间有较多液体存在,常伴各种退行性变。结论腹膜后间隙神经鞘瘤的320排CT表现有特征性,CT表现取决于细胞稀疏区与密集区的比例和排列方式,囊实性多见,呈渐进性延迟轻中度强化,边界清楚,CT对腹膜后神经鞘瘤的定位定性诊断具有重要价值。

Objective To investigate the 320-slice CT features and pathology of retroperitoneal schwannoma,and to evaluate the diagnostic and differential diagnostic efficiency of CT. Methods The CT findings of 22 patients with retroperitoneal schwannoma confirmed by surgical pathology were retrospectively analyzed and compared with pathology. All patients received plain CT scanning and enhanced CT scanning. Results（ 1） Of 22 cases,there were 3 cases with benign schmannoma and 19 cases with malignant schmannoma. The lesions of the 3 cases were located at pelvic extraperitoneal space and the others were located at abdominal retroperitoneal space.（ 2） On CT,3 cases were cystic masses,7 cases were solid masses,12 cases were mixed masses. Benign tumors had a regular margin and malignant tumors had irregular margins.All the tumors showed continuous enhancement. In plain scanning and enhanced scanning with 3 phases,the CT values were（ 35. 40 ± 7. 70） HU、（ 45. 09 ± 8. 71） HU、（ 56. 27 ± 10. 33） HU、（ 68. 64 ± 12. 68） HU. Positioning accuracy of diagnosis was 100%,The accuracy rate of 320-row CT in diagnosis of tumor was 90. 90%（ 20/22）.（ 3） Microscopically Antoni A zone and Antoni B zone could be seen in the tumor. Dense cellular areas are named ＂ Antoni A＂ areas and necrotic hypodense areas as ＂ Antoni B＂ areas. Conclusion Retroperitoneal schwannoma has characteristic features on CT. The features were determined by the proportion and the arrangement of hypocellularity and hypercellularity in the tumor. Mixed masses that showed continuous enhancement were more likely seen. CT is valuable in the diagnosis of retroperitoneal schwannoma.