Hayasaka K, Tanaka Y, Soeda S, Huppert P, Claussen C D
Department of Diagnostic Radiology, Eberhard-Karls University of Tübingen, Germany.
Acta Radiol. 1999 Jan;40(1):78-82. doi: 10.1080/02841859909174408.
To evaluate the MR findings in primary retroperitoneal schwannoma.
Seven cases of primary retroperitoneal schwannoma, in whom the diagnosis was confirmed histopathologically, were analyzed retrospectively. The following items were reviewed at MR imaging: tumor diameter, margin, homogeneity, signal intensity as compared to normal renal parenchyma, presence/absence of infiltration into adjacent organs, and, in 1 and 4 cases, the enhancement on Gd-dynamic images and post-contrast T1-weighted images, respectively.
Tumor diameter was 5.5 +/- 3.1 cm, ranging from 2.5 to 10 cm in the 6 benign schwannomas, and 12 cm in 1 malignant. The tumor margin was regular in all of the benign cases and irregular in the malignant one. The malignant case showed infiltration into the liver and duodenum. Four of the benign schwannomas showed a homogeneous, and 2 presented a heterogeneous pattern, while the malignant schwannoma was heterogeneous. On T1-weighted images, the benign schwannomas were hypointense in 4 cases, isointense in 1 and mixed in 1, while on T2-weighted images, they were hyperintense in 5 and mixed in 1. The malignant case showed mixed intensity on both T1- and T2-weighted images. On enhanced T1-weighted images, capsular, septal enhancement was noted in 2 cases, overall enhancement in 2, and, on Gd-dynamic images, late enhancement was shown.
On MR imaging, primary retroperitoneal schwannomas show different signal intensity characteristics, including cystic degeneration. There are, however, no specific characteristics of these tumors.
评估原发性腹膜后神经鞘瘤的磁共振成像（MR）表现。
回顾性分析7例经组织病理学确诊的原发性腹膜后神经鞘瘤。在MR成像中观察以下项目：肿瘤直径、边缘、均匀性、与正常肾实质相比的信号强度、是否侵犯邻近器官，以及分别在1例和4例中观察钆动态图像和对比剂增强T1加权图像上的强化情况。
肿瘤直径为5.5±3.1cm，6例良性神经鞘瘤直径范围为2.5至10cm，1例恶性神经鞘瘤直径为12cm。所有良性病例的肿瘤边缘规则，恶性病例的边缘不规则。恶性病例显示侵犯肝脏和十二指肠。4例良性神经鞘瘤表现为均匀性，2例表现为不均匀性，而恶性神经鞘瘤为不均匀性。在T1加权图像上，4例良性神经鞘瘤呈低信号，1例等信号，1例混合信号；在T2加权图像上，5例呈高信号，1例混合信号。恶性病例在T1加权和T2加权图像上均表现为混合信号。在增强T1加权图像上，2例可见包膜、分隔强化，2例整体强化，在钆动态图像上显示延迟强化。
在MR成像上，原发性腹膜后神经鞘瘤表现出不同的信号强度特征，包括囊性变。然而，这些肿瘤没有特异性特征。
