Histopathological re-evaluation of pancreatic epithelial lesions : PanIN and IPMN

我们利用免疫组织化学和分子生物学对胰腺上皮病变进行了组织病理学重新评估，特别是PanIN和IPMN。然后，我们试图找到IPMN的早期病变，并考虑PanIN和IPMN可能发展为胰腺癌的途径。PanIN-1的发生率较高；然而，PanIN-3的发生率非常罕见，特别是在尸检病例中。我们有时在胃型IPMNs周围同时发现PanIN-1和PanIN-2病变。这提示IPMN可能来自PanIN-1或panin - 2。关于导管的癌变，至少有两种类型的导管癌变。关于IPMN亚型，迄今为止至少提出了四种亚型。它们是胃型、肠型、胰胆型和嗜瘤细胞型。综合这些IPMN亚型，我们认为胰胆管型和嗜酸细胞型IPMN都可能来源于胃型IPMN，胰胆管型和嗜酸细胞型IPMN应被视为胃型IPMN的高级别病变。此外，我们发现另一种类型的导管内肿瘤缺乏粘蛋白。从细胞学的角度来看，这四种亚型应在细胞学标本中进行评估，因为这些亚型的预后不同。

We performed the histopathological re-evaluation of pancreatic epithelial lesions, especially PanIN and IPMN by using immunohistochemistry and molecular biology. Then, we tried to find the incipient lesion of IPMN and considered the possible pathway of developing pancreatic cancer from PanIN as well as IPMN. The incidence of PanIN-1 was relatively high ; however, the incidence of PanIN-3 was very rare especially in autopsy cases. We sometimes noted the coincidental PanIN-1 and PanIN-2 lesions around gastric type IPMNs. This may suggest the possible pathway of IPMN from PanIN-1 or 2. Regarding the cancerization of the duct, there were at least two types of cancerization of the ducts.Concerning IPMN subtypes, so far at least four subtypes have been proposed. These are gastric type, intestinal type, pancreatobiliary type, and oncocytic type. Reviewing these IPMN subtypes, we postulated that both pancreatobiliary type and oncocytic type were probably derived from gastric type IPMNs, and the pancreatobiliary type and oncocytic type IPMN should be regarded as high grade lesions of gastric type IPMNs. In addition, we found another type of intraductal tumor with scant mucin.From the cytological point of view, these four subtypes should be evaluated in cytology specimens since the prognosis differs according to these subtypes.