胰腺乏血供神经内分泌肿瘤的CT表现及误诊分析

Analysis of CT findings and misdiagnosis of pancreatic neuroendocrine tumors with poor blood supply

目的:探讨乏血供胰腺神经内分泌肿瘤(pNETs)的影像学特征及误诊情况。方法:回顾性分析经手术病理证实的15例乏血供pNETs。分析肿块的位置、形状、边界,有无钙化、胰胆管扩张、局部侵犯或转移、远端胰尾萎缩,以及强化方式等。结果:15例中中级别pNETs 2例,高级别pNETs 13例,皆为单发;病灶直径2.70～7.40 cm,平均(4.58±1.60)cm;位于胰头5例(33.3%),胰体6例(40.0%),胰尾4例(26.7%);边界清晰8例(53.3%),边界不清7例(46.7%);1例(6.7%)病灶内有钙化;3例(20.0%)胰管扩张;2例(13.3%)胆管扩张;3例(20.0%)可见胰尾萎缩;6例(40.0%)有周围侵犯或远处转移。增强扫描病灶呈轻中度强化,增强扫描各期(动脉期、静脉期、延迟期)病灶的强化程度均低于周围正常胰腺实质,且呈乏血供表现,病灶门脉期强化程度高于动脉期,延迟期略下降。术前仅3例(20.0%)正确诊断,10例(66.7%)误诊为胰腺癌,2例(13.3%)误诊为囊腺癌。结论:乏血供pNETs虽具有一定特征性影像学表现,但与胰腺癌等有相似之处,鉴别困难。

Objective:To analyze the imaging features and misdiagnosis of pancreatic neuroendocrine tumors(pNETs)with poor blood supply.Methods:Fifteen patients with pNETs lack of blood supply confirmed by operation and pathology were analyzed retrospectively.The location,shape,boundary,calcification,dilatation of pancreaticobiliary duct,local invasion or metastasis,atrophy of pancreatic tail and enhancement were analyzed.Results:Among the 15 patients with pNETs,2 cases were G2 and 13 patients were G3,all of them were single.The diameter of the lesion was 2.70~7.40 cm[mean(4.58±1.60)cm];5(33.3%)cases of tumors located in the head of pancreas,6(40%)cases of tumors located in the body of pancreas,4(26.7%)cases of tumors located in the tail of pancreas.The boundary of the lesion was clear in 8 cases(53.3%),the boundary was unclear in 7 cases(46.7%);calcification was observed in 1(6.7%)case;3(20%)cases had dilatation of pancreatic duct;2(13.3%)cases had dilatation of bile duct;and 3(20%)cases had pancreatic tail atrophy.6(40%)cases with peripheral invasion or distant metastasis.The enhancement degree of each phase(arterial phase,venous phase,delayed phase)was lower than that of the surrounding normal pancreatic parenchyma,and the lesion showed lack of blood supply during dynamic enhancement.The enhancement degree of portal vein phase was higher than that of arterial phase,and the delayed phase was sligtly decreased.Preoperative diagnosis was correct in only 3(20.0%)cases,10(66.7%)cases were misdiagnosed as pancreatic cancer,2(13.3%)cases were misdiagnosed as cystadenocarcinoma.Conclusion:Although pNET with poor blood supply has some imaging features,it has many similarities with pancreas cancer and other diseases,so it is difficult to be distinguished.