Evaluation of various imaging methods in the differential diagnosis of intraductal papillary-mucinous tumor (IPMT) of the pancreas.
Evaluation of various imaging methods in the differential diagnosis of intraductal papillary-mucinous tumor (IPMT) of the pancreas.
复制标题
不同影像学方法在胰腺导管内乳头状粘液瘤（IPMT）鉴别诊断中的评价。
作者：
K. Yamao;K. Ohashi;T. Nakamura;T. Suzuki;Y. Watanabe;Y. Shimizu;Y. Nakamura;I. Ozden
背景/目的
胰腺导管内乳头状黏液瘤具有独特的临床病理特征。表现出IPMT特征性临床特征的病变表现出广泛的组织学类型，从不典型增生到浸润性癌。因此，不能推荐所有IPMT患者进行手术治疗。有必要评估IPMT在个体患者中的恶性潜力，以选择合适的方法。本研究的目的是评价超声内镜和导管内超声检查的有效性，并与超声检查和计算机断层扫描进行比较。
方法
对49例IPMT（不典型增生7例，腺瘤23例，非浸润性7例，浸润性腺癌12例）进行了超声、CT、超声内镜及导管内超声检查。根据另28例IPMT切除标本的组织病理学分析，影像学鉴别诊断标准如下：非肿瘤性病变（不典型增生）：无管壁增厚或结节;非侵入性IPMT（腺瘤和导管内癌）：存在结节或管壁增厚;侵袭性IPMT伴胰腺实质浸润：具有异质性模式的肿块或肿块中断胰管壁。
结果
超声、CT、超声内镜和导管内超声对非肿瘤性病变、非侵袭性IPMT和侵袭性IPMT的诊断准确率分别为33%、38%、77%和67%。超声鉴别肿瘤性和非肿瘤性IPMT的敏感性、特异性和准确性分别为33%、100%、42%，CT为36%、100%、44%，超声内镜为90%、71%、88%，导管内超声为94%、29%、84%。超声诊断有创性和无创性IPMT的敏感性、特异性和准确性分别为25%、100%、80%，CT为33%、100%、83%，超声内镜为55%、97%、88%，导管内超声为56%、91%、84%。根据检查结果显示较高级别病变，内镜超声检查和导管内超声检查对侵入性IPMT（除微创病例外）的诊断准确率为80%。
结论
根据这些标准，超声检查和计算机断层扫描显示出高特异性，但对肿瘤性/非肿瘤性和侵袭性/非侵袭性IPMT的鉴别诊断敏感性较低。然而，超声内镜和导管内超声检查具有较高的敏感性和诊断准确性的肿瘤性/非肿瘤性病变的鉴别诊断。超声内镜和导管内超声联合诊断侵袭性IPMT的准确率高。因此，内镜超声检查和导管内超声检查对IPMT治疗方法的选择有重要意义。
BACKGROUND/AIMS
IPMT (intraductal papillary-mucinous tumor) of the pancreas has unique clinicopathological characteristics. The lesions which show characteristic clinical features of IPMT exhibit a wide spectrum of histological types ranging from atypical hyperplasia to invasive cancer. Therefore, surgical treatment cannot be recommended for all patients with IPMT. It is necessary to assess the malignant potential of IPMT in individual patients in order to select an appropriate approach. The aim of this study was to evaluate the effectiveness of endoscopic ultrasonography and intraductal ultrasonography as compared with ultrasonography and computed tomography for this purpose.
METHODOLOGY
Ultrasonography, computed tomography, endoscopic ultrasonography and intraductal ultrasonography were performed in 49 cases of IPMT (atypical hyperplasia 7, adenoma 23, noninvasive 7 and invasive adenocarcinoma 12). On the basis of the histopathological analysis of another 28 cases of resected IPMT specimens, criteria for differential diagnosis by imaging modalities were defined as follows: Nonneoplastic lesion (atypical hyperplasia): no wall thickening or nodule; noninvasive IPMT (adenoma and intraductal carcinoma): a nodule or wall thickening is present; and invasive IPMT with pancreatic parenchymal invasion: a mass with a heterogenous pattern or interruption of the pancreatic duct wall by the mass.
RESULTS
The diagnostic accuracy rate for differentiating nonneoplastic lesion noninvasive IPMT, and invasive IPMT was 33% by ultrasonography, 38% by computed tomography, 77% by endoscopic ultrasonography, and 67% by intraductal ultrasonography. Sensitivity, specificity and accuracy rates for differentiating neoplastic and nonneoplastic IPMT by ultrasonography was 33%, 100%, 42%, by computed tomography 36%, 100%, 44%, by endoscopic ultrasonography 90%, 71%, 88%, by intraductal ultrasonography 94%, 29%, 84%, respectively. Sensitivity, specificity and accuracy rates for differentiating invasive and noninvasive IPMT by ultrasonography was 25%, 100%, 80%, by computed tomography 33%, 100%, 83%, by endoscopic ultrasonography 55%, 97%, 88%, by intraductal ultrasonography 56%, 91%, 84%, respectively. Diagnostic accuracy for invasive IPMT except minimally invasive cases by endoscopic ultrasonography and intraductal ultrasonography was 80%, based on the results of the examination which demonstrated a higher grade lesion.
CONCLUSIONS
With these criteria, ultrasonography and computed tomography showed high specificity, but low sensitivity for the differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive IPMT. However, endoscopic ultrasonography and intraductal ultrasonography had high sensitivity and diagnostic accuracy for the differential diagnosis of neoplastic/nonneoplastic lesions. Combination of endoscopic ultrasonography and intraductal ultrasonography showed a high accuracy rate in the diagnosis of invasive IPMT. Thus endoscopic ultrasonography and intraductal ultrasonography contributed significantly to the choice of the treatment for IPMT.