24例胰腺实性-假乳头状瘤的螺旋CT征象与临床病理分析

Clinicopathological Analysis of CT Findings of Solid Pseudopapillary Tumor in the Pancreas: A Report of 24 Cases

目的:分析胰腺实性-假乳头状瘤的螺旋CT征象及病理特点,提高术前诊断水平。方法:回顾性分析24例胰腺SPT的螺旋CT征象,包括肿瘤的部位、大小、形态、边界、密度、强化方式、强化程度、囊实比例、钙化、临近组织器官侵犯及淋巴结转移等,并与手术结果及病理对照分析。结果:1)肿瘤发生于胰头部10例,体部7例,尾部6例,体尾部1例,大部分呈圆形或类圆形,部分有分叶,边界清楚,有完整包膜。2)肿瘤内部可见实性及囊性成分,实性部CT平扫呈稍低或等密度,增强扫描动脉期轻至中度强化,门脉期进一步强化,与胰腺实质最大密度差出现在动脉期,囊性部分平扫及增强扫描均呈低密度。3)囊性为主型6例,实性为主型8例,囊实相仿型10例。4)8例肿瘤内部可见钙化,其中一例呈蛋壳状钙化,6例胰管轻度扩张,1例胆总管、肝内胆管可见扩张。5)9例患者CT征象见恶性倾向,1例呈弥漫性生长,5例推压、包绕脾血管,2例与肠系膜血管粘连,1例肿瘤包绕右肾静脉,其余15例CT表现为良性,包膜完整,与周围器官、组织分界清楚,术中所见有一定差异。结论:胰腺SPT病理学特点明显,螺旋CT征象有一定特征,肿瘤呈囊实性两部分,血供较为丰富,呈逐渐强化改变,与大多数胰腺癌缺乏血供有较大差别,血浆CEA阴性也有较大的参考价值,CT检查对胰腺SPT的术前诊断、良恶性判断、治疗方法的选择均有重要意义。

Objective： To characterize the multi-slice spiral computed tomographic （MSCT） findings and clinicopathology of solid pseudopapillary tumor （SPT） in the pancreas. Methods： The MSCT images of 24 patients with pathologically and immunohistochemically identified SPTs were reviewed. Tumor location, size, contour, boundary, enhancement patterns, degree of enhancement, percentage of necrosis, and calcification of the tumors were observed. The invasion to the adjacent organs and structures and lymph node metastases were analyzed. Results： （1） Of the 24 patients whose MSCT scan images were reviewed, 10 had SPTs in the head of the pancreas, 7 in the body of the pancreas, 6 in the tail of the pancreas, and 1 bestride the body and the tail of the pancreas. （2） There were solid and cystic structures within the neoplasms. The cystic portions appeared hypo-attenuation on both pre-and post-contrast views. The solid portions demonstrated hypoor iso-attenuation on pre-contrast MSCT scans, slight or midrange enhancement in the arterial phase and marked enhancement in the portal venous phase on post-contrast MSCT scans. The maximal density contrast beween the solid portions and the pancreatic tissues could be observed in the arterial phase. （3） Six lesions were mainly composed of cystic structures and their solid portions under the capsule appeared as mural nodules. Eight lesions were mainly composed of solid structures with cystic portions near or under the capsule, and 10 lesions were composed of similar proportions of cystic and solid parts distributed alternatively. （4） Eight lesions had calcification within the tumors, 6 lesions were accompanied with associated dilatation of the pancreatic duct, and 1 lesion was accompanied with dilatation of the common bile duct and intrahepatic bile ducts. （5） Nine tumors had malignant tendency, one of which displayed diffused growth. Five lesions were circumvoluted with the blood vessels of the spleen, 2 tumors adhered to the blood vessels of the mesentery, and 1 tumor was circumvoluted with the vena renalis dextra. Other tumors with complete capsules and with-out invasion to the adjacent organs and structures were diagnosed as benign. There were a few differences between the surgical findings and MSCT scans. Conclusion： The MSCT of SPTs has distinct features and is helpful for the prediction of the malignant risk of SPTs in the pancreas.