胰腺实性假乳头状肿瘤临床病理特征及LEF-1在其诊断中的应用价值

The clinicopathological features of solid pseudopapillary neoplasm of the pancreas and the application of LEF-1 in its diagnosis

目的 探讨胰腺实性假乳头状肿瘤（SPN）的临床病理特征及淋巴细胞增强因子1（LEF-1）表达在其诊断中的应用价值.方法 收集并分析长海医院2000年1月至2015年12月间病理确诊为SPN的227例患者的临床病理资料,采用免疫组织化学方法检测132例SPN中LEF-1的表达,并与诊断SPN最常用的标志物β-catenin等的表达进行比较.结果 81.9%（186/227）的SPN发生于女性,发病平均年龄34岁;肿瘤平均直径为5.4 cm;48.5% SPN位于胰体尾部,33.0%位于胰头部;46.3%的肿瘤呈囊实性,42.3%呈实性,11.4%呈囊性.镜下观察有2例（0.9%）出现淋巴结转移,15例（6.6%）有脉管癌栓,14例（6.2%）有神经侵犯,13例（5.7%）侵犯邻近脏器.免疫组织化学结果显示,132例SPN中130例LEF-1呈核强阳性表达,阳性率为98.5%,而周围正常胰腺组织及胰腺其他肿瘤均未见LEF-1表达,特异性为100%.SPN的β-catenin阳性率为96.6%（144/149）,但有1例腺泡细胞癌呈阳性表达,特异性降低.165例术后平均随访51个月,截止至2016年10月31日,162例（98.2%）存活,5例出现肝脏转移,1例复发.结论 SPN好发于年轻女性,临床表现无特异性.LEF-1可作为SPN诊断和鉴别诊断的特异性标志物之一,且较β-catenin更为准确.

Objective To analyze the application of clinicopathological features and LEF-1 in the diagnosis of solid pseudopapillary neoplasm of the pancreas （SPN）.Methods Clinical and pathological data of 227 cases who were pathologically diagnosed as pancreatic SPN at Changhai Hospital from Jan 2000 to Dec 2015 were collected and analyzed.Immunochemical assay was used to detect the expression of LEF-1 in 132 cases of SPN, and the results were compared with β-catenin, which is most commonly used for diagnosing SPN.Results 81.9% of patients with SPN were female （186/227）.Mean age at the onset was 34 years.Mean tumor size was 5.4 cm.48.5% tumors were localized in the pancreatic tail, and 33% in the head.46.3% tumors were cystic and solid, 42.3% were solid, and 11.4% were cystic.There were 2 cases of lymph node metastasis （0.9%）, 15 cases of vascular tumor thrombus （6.6%）, 14 cases of nerve invasion （6.2%）, and 13 cases of adjacent organs invasion （5.7%） based on microscopic observations.Immunochemical analysis showed that 130 of 132 cases with SPN expressed LEF-1 with strong nuclear positivity, and the positivity rate was 98.5%.But no obvious expression of LEF-1 can be seen in normal pancreatic tissue and other pancreatic tumors.The specificity was 100%.The positivity of β-catenin expression in SPN was 96.6%（144/149）, and β-catenin was positively expressed in only one case of acinar cell carcinoma.Tumors were completely removed by surgery in 165 cases, and the median follow-up was 51 months.By Oct 31, 2016, 162 patients （98.2%） survived, 5 had liver metastasis, and 1 had recurrence.Conclusions SPN is predominantly encountered in young female patients, and the clinical manifestations are not specific.LEF-1 can be used as a specific marker for the diagnosis and differentiation of SPN, which is more accurate than β-catenin.