腹部肾上腺外、脊柱副节瘤CT、MRI表现与病理对照分析

Abdominal Extra-adrenal and Spinal Paraganglioma: CT, MRI Finding-Pathologic Correlation

目的探讨腹部肾上腺外(腹膜后、膀胱)、脊柱副节瘤的影像学特征,以及三期动态增强扫描的诊断价值。方法回顾分析19例经病理证实的腹部肾上腺外、脊柱副节瘤CT(n=17)、MRI(n=3)资料,将CT、MRI表现与病理对照。结果 19例均单发,其中,腹膜后12例,CT平扫病灶均呈不均匀稍低密度,增强后均呈中度/明显强化,其中,4例呈"渐进性延迟强化",镜下所见:瘤细胞排列呈小腺泡状或实性巢状,间质毛细血管丰富;各6例、2例强化模式呈"快进慢出"、"慢进慢出"型,镜下所见:瘤细胞形成器官样结构,间质内见中等/大量血窦影。膀胱5例,平扫均呈均匀稍低密度/稍长T1等T2信号,动态增强扫描,增强模式呈"快进慢出"型,镜下所见:瘤细胞呈小梁/巢状排列,间质血窦丰富。脊柱2例,病灶内均可见点、匍匐条状流空血管影;均未见淋巴结转移,1例腹膜后病例出现腰椎体及附件转移。结论腹部肾上腺外副节瘤CT、MRI表现具有一定特征,三期动态增强扫描可较好反映肿瘤内部构成,具有较高诊断价值;脊柱副节瘤较少见,诊断困难,病灶内"点状、匍匐条状流空血管征"可能具有一定特征。

Objective To explore the CT and MRI features of abdominal extra-adrenal and spinal paraganglioma and the diagnosis value of three phases dynamic enhancement scanning for it.Methods The CT and MRI findings of 19 patients pathologically confirmed abdominal extra-adrenal and spinal paraganglioma were retrospectively studied and compared with pathological features.Results Single tumor was found in all 19 patients. The disease was located in the retroperitoneum in 12 cases. On the CT plain scan, the leision presented as slightly low attenuation, while in three-phase dynamic enhancement scanning, 4 of them showed ＂progressive delayed enhancement＂. The histologic examination showed tumor cells are arranged in an alveolar or nesting pattern, with abundant capillaries in interstitial substance. 6 cases showed ＂slow in and slow out＂ enhanced mode and 2 cases showed ＂fast in and slow out＂ enhanced mode. Histopathologically, tumor cells formed in organoid patterns, surrounded moderate or abundant hematococoel. 5 cases located in urinary bladder. The leision manifested as homogeneous isodensity on the CT palin scan and slightly hypointensity on T1WI and isointensity on T2WI, while in three-phase dynamic enhance scan, they enhanced obviously in the artery phase, and then drop slowly in the portal and delay phase. Histopathologically, tumor cells showed string-like or nesting pattern , surrounded moderate or abundant hematococoel. 2 cases located in the spine, and multiple punctate and serpiginous structures of signal void due to high-velocity flow were noted around and within the tumors on all sequences were seen. None had lymphatic metastasis, while lumbar vertebral body and accessory metastasis occurred in one case.Conclusion There are certain characteristics of abdominal extra-adrenal paraganglioma, on the CT or MRI imaging. CT dynamic enhancement scanning has a preferable diagnosis value, because it can reasonably reflect the inner composition of the tumors. Paragangliomas occurring in spine are extremely rare, and it is very difficult to diagnose, but the multiple punctate and serpiginous structures of signal void around and within the tumors on all sequences may be the characteristic sign of it.