胰腺实性假乳头肿瘤诊断及鉴别诊断标志物的筛选

Immunohistochemical markers for the differential diagnosis of pancreatic solid-pseudopapillary neoplasm

目的:分析不同免疫学标志在胰腺实性假乳头肿瘤(solid-pseudopapillary neoplasm,SPN)中的诊断及鉴别诊断价值,以筛选有确诊意义的免疫标志物。方法:分别制作55例SPN、51例胰腺神经内分泌肿瘤(pancreaticneuroendocrine tumor,P-NET)和54例胰腺腺癌(pancreatic adenocarcinoma,PAC)的组织芯片,另收集19例SPN、6例胰腺腺泡细胞癌(acinar cell carcinoma,ACC)、1例胰母细胞瘤(pancreatoblastoma,PB)的手术标本,用免疫组织化学法检测CD99、E-cadherin、β-catenin、P120及其他普遍用于SPN辅助诊断的免疫学标志物在以上各类肿瘤中的表达情况。结果:CD99在所有SPN肿瘤细胞中均显示出独特的核旁点状着色,40例P-NET则显示CD99细胞膜或细胞质及膜阳性着色,4例PAC及1例PB表现出CD99弱膜阳性,而所有ACC细胞均无CD99表达。所有SPN细胞均不表达E-cadherin,β-catenin呈细胞核和细胞质强阳性染色,46例P-NET、52例PAC、6例ACC、1例PB的肿瘤细胞存在E-cadherin膜表达;所有51例P-NET、54例PAC、6例ACC、1例PB肿瘤细胞均有β-catenin膜表达。59例SPN细胞质出现P120着色,6例细胞膜出现P120着色;38例P-NET的细胞质中有P120表达,8例细胞膜上有P120表达;PAC、ACC、PB中分别有48例、5例、1例肿瘤细胞细胞膜表达P120,但未见细胞质中有其表达。其他标志物中,71例SPN、19例P-NET、4例PAC表达PR;59例SPN、46例P-NET、5例PAC表达CD10;66例SPN、45例P-NET、2例PAC表达CD56;72例SPN、48例P-NET、3例PAC表达NSE;ACC及PB对以上各项标志物均呈阴性。结论 :CD99的核旁点状着色是诊断SPN最可靠的免疫学标志,β-catenin和E-cadherin在SPN的诊断及鉴别诊断中也有重要意义。

Objective To study the diagnostic value of various immunohisochemical markers and to identify the most useful marker for the definitive diagnosis of pancreatic solid-pseudopapillary neoplasm （SPN）. Methods： Immunohis- tochemical staining CD99, E-cadherin, β-catenin, P120 and other markers used for the diagnosis of SPN were tested in tissue microarray blocks from 55 cases of SPN, 51 cases of pancreatic neuroendocrine tumor （P-NET）, and 54 cases of pancreatic adenocarcinoma （PAC）. Surgical specimens from 19 SPN,6 pancreatic acinar cell carcinoma （ACC） and 1 pan- creatoblastoma （PB） were also investigated. Results： All the SPN cells exhibited paranuclear dot-like immunoreactivity of CD99 regardless the clinicopathological or morphological features. Forty of the 51 P-NET were positive for CD99 on cell membrane and/or cytoplasm. Four of the 54 PAC and 1 PB showed faint membrane staining. None of the ACC was reactive for CD99. All the SPN cases were negative for E-cadherin and positive for nuclear and cytoplasm β-catenin. Forty-six P-NET, 52 PAC, 6 ACC and 1 PB were E-cadherin membrane positive. All the P-NET, PAC, ACC, PB cases were β- catenin membrane positive. Fifty-nine SPN and 38 P-NET were P120 cytoplasm positive. Six SPN, 8 P-NET, 48 PAC, 5 ACC and 1 PB were P120 membrane positive. Seventy-one SPN, 19 P-NET and 4 PAC were PR nuclear positive. Fifty-nine SPN, 46 P-NET and 5 PAC were positive for CD10. Sixty-six SPN, 45 P-NET and 2 PAC were positive for CD56. Seventy-two SPN, 48 P-NET and 3 PAC were positive for NSE. All the ACC and PB were negative for PR, CD10, CD56 and NSE. Conclu- sions： The unique dot-like staining pattern of CD99 in SPN is the most useful immuno-marker for definitive diagnosis of SPN and differentiation from other pancreatic tumors. β-catenin and E-cadherin are also helpful for the diagnosis of SPN.