胰腺实性假乳头状肿瘤良恶性影像学鉴别诊断

Differentiation Between Benign and Malignant Solid Pseudopapillary Tumor of the Pancreas by CT and MRI

目的探讨胰腺实性假乳头状肿瘤(SPN)良恶性的CT和MRI鉴别诊断特征。方法由3名影像诊断医师对47例经手术病理证实的SPN患者的CT和MRI图像进行回顾性分析。采用Pearsonχ~2检验或Fisher确切概率法分析以下影像学指标:肿瘤位置,边缘形态,实性成分比例,包膜形态,钙化形态,上游胰管是否扩张,是否存在血管侵犯、周围组织浸润和远处转移。结果 82.3%的良性SPN常常呈圆形、椭圆形或边缘波浪状,53.8%的恶性SPN常常呈边缘分叶状(P=0.032)。绝大多数良性胰腺实性假乳头状肿瘤包膜完整(26/34,76.5%),包膜局部不连续常常出现在恶性胰腺实性假乳头状肿瘤(7/13,53.8%)(P=0.001)。结节样和散在钙化、上游胰管扩张、血管侵犯、周围组织浸润和远处转移仅出现在恶性胰腺实性假乳头状肿瘤(P均<0.001)。其他影像学表现良性和恶性胰腺实性假乳头状肿瘤无统计学差异。结论边缘分叶状、包膜局部不连续、结节样和散在钙化以及上游胰管扩张提示恶性可能,出现血管侵犯、周围组织浸润和远处转移可以确定恶性诊断。

Objective To investigate differential imaging features between benign and malignant solid pseudopapillary neoplasms(SPN)of the pancreas on computed tomographic and magnetic resonance images.Methods The computed tomographic and magnetic resonance images of 47 patients with confirmed SPN by surgery and pathology were reviewed by 3 radiologists in consensus according to the following features of the lesions:location of tumor,tumor margin,proportion of solid component,morphology of capsule,calcification,presence of upstream pancreatic ductal dilatation,angioinvasion,invasion of the surrounding organs,and metastasis.The comparisons of rates were carried out byχ~2 test or Fisher’s exact probabilities.Results 82.3%Benign SPN usually had round,oval,or wavy margins,whereas 53.8%malignant SPN more commonly had lobulated margins(P=0.032).The majority of benign SPN had a complete capsule(76.5%),whereas focal discontinuity of the capsule was more commonly seen in malignant SPN(53.8%)(P=0.001).Nodular and scattered calcification,upstream duct dilatation,angioinvasion,invasion of the surrounding organs,and metastasis were only seen in malignant SPN(P<0.001,P<0.001,P<0.001,P=0.001,respectively).There was no statistical differences between benign and malignant tumors in other imaging findings.Conclusion A lobulated margin,a focal discontinuity of the capsule,a nodular or scattered calcification,and upstream duct dilatation may suggest malignant SPN,meanwhile angioinvasion,invasion of the surrounding organs,and metastasis were malignant SPN definitely.