The incidence of well-differentiated non-functioning pancreatic neuroendocrine tumors (NF-PanNET) increased during the last decades. The risk of relapse after curative surgery, albeit low, is not negligible; moreover, adjuvant treatment is currently not an option and a reliable predictive model based on prognostic characteristics is urgently needed for tailoring a follow-up strategy. The histological classification of PanNET now relies only on the proliferative activity (mitosis and Ki67) and staging. In contrast to other endocrine neoplasms, the role of infiltrative growth pattern in NF-PanNET is not taken into consideration at present. In the current study, 247 consecutive patients who underwent surgical resection for a NF-PanNET were examined for the histological growth pattern of the tumor. Two distinct patterns (non-infiltrative vs. infiltrative) were described with the latter being further subclassified according to the type of structures invaded by the tumor (non-infiltrative: pattern 1; infiltration of adjacent pancreatic parenchyma and/or peripancreatic soft tissue: pattern 2; invasion of nearby organs and/or major vessels: pattern 3). The infiltrative growth resulted to be strongly associated with a poorer survival compared to a non-infiltrative growth (p < 0.001). In particular, the distinction between pancreatic parenchyma and/or peripancreatic soft tissue invasion versus adjacent organs and/or major vessels invasion was the most powerful predictor of recurrence after surgery at multivariate analysis (pattern 2 vs. pattern 1: HR 10.136, p = 0.028; pattern 3 vs. pattern 1: HR 15.775, p = 0.015). The infiltrative growth pattern could therefore provide additional prognostic information implementing the current grading and staging system.

在过去几十年中，分化良好的无功能胰腺神经内分泌肿瘤 (NF-PanNET) 的发病率有所增加。根治性手术后复发的风险虽然很低，但也不容忽视；此外，辅助治疗目前不是一种选择，迫切需要一种基于预后特征的可靠预测模型来制定后续策略。PanNET 的组织学分类现在仅依赖于增殖活性（有丝分裂和 Ki67）和分期。与其他内分泌肿瘤相比，目前尚未考虑 NF-PanNET 中浸润性生长模式的作用。在当前的研究中，对 247 名连续接受 NF-PanNET 手术切除的患者进行了肿瘤组织学生长模式的检查。两种不同的模式（非浸润性与浸润性）进行了描述，后者根据肿瘤侵入的结构类型进一步细分（非浸润性：模式 1；邻近胰腺实质和/或胰周软组织的浸润：模式 2；附近器官和/ 或主要血管：模式 3)。与非浸润性生长相比，浸润性生长与较差的存活率密切相关 ( p  < 0.001)。特别是，胰腺实质和/或胰周软组织侵犯与邻近器官和/或大血管侵犯之间的区别是多变量分析中手术后复发的最有力预测因素（模式 2与模式 1：HR 10.136，p = 0.028；模式 3与模式 1：HR 15.775，p  = 0.015）。因此，浸润性生长模式可以提供实施当前分级和分期系统的额外预后信息。