儿童胰腺实性-假乳头状肿瘤8例临床病理学分析

Pancreatic solid-pseudopapillary tumors in children: clinicopathological analyses of 8 cases

目的探讨儿童胰腺实性假乳头状肿瘤(SPPT)的临床病理特征及预后,以期提高对儿童SPPT的认识。方法对2007—2017年间收集的8例儿童SPPT的常规病理及免疫组化进行观察,回顾复习8例SPPT的临床资料并复习相关文献,探讨其组织发生及生物学行为。结果 SPPT常为边界清楚的囊实性或实性的肿瘤结节,镜下由较一致的中等大肿瘤细胞组成,以实性区、假乳头状区和囊性区以不同比例混合。假乳头表面被覆多层肿瘤细胞,大多数肿瘤细胞核远离纤维血管轴心,类似室管膜样的假菊形团结构。免疫组化:肿瘤细胞α-AT、vimentin、β-caternin、Claudin-5、PR、CD10均(+),而E-cadherin(-),内分泌标记物CD56、NSE、Syn、CgA(+),Ki-67指数低。结论 SPPT是儿童胰腺罕见的一种低度恶性肿瘤,即使伴有肿瘤周围组织的浸润,只要被完整切除均有很好的预后,该肿瘤可能起源于胰腺原始多潜能干细胞,SPPT的分子表达主要集中在Wnt/β-caternin及Notch信号通路,导致β-caternin抗体在肿瘤的细胞核与细胞质表达及E-cadherin免疫组化的失表达,性激素可能在SPPT生长中扮演重要的角色,典型的组织像结合α-AT、vimentin、β-caternin、Claudin-5、PR、CD10、E-cadherin等免疫组化标记物可对SPPT做出诊断与鉴别诊断。

Purpose To investigate the clinicopahological characteristics and prognosis in 8 cases of solid pseudopapillary tumor of the pancreas in children,and to improve the understanding of the disease. Methods Eight cases of SPPT were observed with conventional histopathologic analysis and immunohistochemistry from 2007 to 2017. Retrospective review was conducted with clinical data and the related literature was reviewed to analyze the histogenesis and biological behavior of the disease. Results Tumors were cystic and solid or solid nudules with clear borderline. Microscopic evaluation revealed that the tumor was composed of medium-sized cells with different proportions of solid,papillary and cystic structures. The papillary surface was covered with multilayer tumor cells; most tumor nuclei were away from the fibrovascular axis,similar to the pseudorossette structure. Immunohistochemically,the tumors were usually positive for α-AT,vimentin,β-caternin,claudin-5,PR and CD10,but usually negative for E-cadherin; the tumors could express endocrine markers,such as CD56,NSE,Syn and CgA. Ki-67 index was low. Conclusions SPPT is a tumor with low malignancy of the pancreas in children; the prognosis is better if the tumor has been completely resected even with the infiltration of tumor surrounding tissue. The tumor may originate from the pancreatic primordial pluripotent stem cell. Molecular expression of SPPT is mainly focused on Wnt/beta-caternin and Notch signaling pathways,leading to beta-caternin expression in the nucleus and cytoplasm,and loss expression of E-cadherin. Sex hormones may play an important role in SPPT growth. Typical histological features and expression of some immunohistochemical markers（ α-AT,vimentin,β-caternin,Claudin-5,PR,CD10 and E-cadherin） can help diagnosis and differential diagnosis for SPPT.