Division of Gastroenterological and General Surgery, Department of Surgery, Asahikawa Medical University, Hokkaido, Japan.
Pancreas. 2011 May;40(4):588-94. doi: 10.1097/MPA.0b013e31820d1a03.
The aim of this study was to define the relevance of mural nodules (MNs) as a "direct" indicator of malignancy of intraductal papillary mucinous neoplasm (IPMN) of the pancreas.
Thirty-nine surgically resected IPMNs excluding obviously invasive carcinomas were examined. The distribution of the most severely dysplastic lesions was mapped on specimens. Immunohistochemical analysis for MUC1 and MUC2 was performed on sections containing the histologically predominant lesions and the most severely dysplastic areas.
The presence of MNs correlated well with the histological grade of IPMN (P < 0.01); however, the most severely dysplastic lesions were associated with a flat/nonelevated area rather than MNs (78.9%). In the MUC1-positive subgroup, minimally invasive carcinoma was colocalized to MNs, whereas most severely dysplastic foci including minimally invasive carcinoma with components of mucinous and tubular adenocarcinoma were observed in the areas apart from MNs in the MUC2-positive and MUC1/2-negative subgroups, respectively.
Although our data support the concept that MNs represent areas of higher-grade dysplasia within IPMN, development of invasive lesions from MNs may be limited to cases that are MUC1-positive. Careful attention should be paid to the emergence of invasive IPMN from flat foci in MUC2-positive and MUC1/2-negative cases.
本研究旨在确定壁结节（MNs）作为胰腺导管内乳头状黏液性肿瘤（IPMN）恶性程度的“直接”指标的相关性。
检查了 39 例手术切除的 IPMN，不包括明显侵袭性癌。在标本上绘制最严重异型增生病变的分布。对包含组织学主要病变和最严重异型增生区域的切片进行 MUC1 和 MUC2 的免疫组织化学分析。
MNs 的存在与 IPMN 的组织学分级密切相关（P<0.01）；然而，最严重异型增生病变与平坦/无隆起区域相关，而不是 MNs（78.9%）。在 MUC1 阳性亚组中，微浸润癌与 MNs 共存，而在 MUC2 阳性和 MUC1/2 阴性亚组中，除 MNs 外，分别在远离 MNs 的区域观察到包括微浸润癌和黏液性及管状腺癌成分的最严重异型增生灶。
尽管我们的数据支持 MNs 代表 IPMN 内高级别异型增生区域的概念，但 MN 中侵袭性病变的发展可能仅限于 MUC1 阳性病例。应密切关注 MUC2 阳性和 MUC1/2 阴性病例中从平坦病灶发展而来的侵袭性 IPMN。
