伴微乳头状分化的胃肠道腺癌的临床病理学特征和免疫组织化学研究

Gastrointestiual adenocarcinomas with a micropapillary pattern： a clinicopathologic and immunohistochemical study

目的 探讨伴微乳头状分化的胃肠道腺癌（GAMPD）的临床病理特征及上皮细胞膜抗原（EMA）、胰岛素样生长因子Ⅱ mRNA结合蛋白-3（IMP3）和E-cadherin表达的临床意义.方法 对73例GAMPD进行临床病理学分析,并应用免疫组织化学EnVision法检测EMA、IMP3和E-cadherin 在GAMPD中的表达.结果 在73例GAMPD中,微乳头状癌分化成分所占比例为5%～70%,多见于中分化腺癌.与普通腺癌比较,GAMPD在转移阳性淋巴结和TNM分期上存在明显差异.淋巴结转移性微乳头状癌成分与原发灶微乳头状癌成分含量呈正相关.微乳头状癌细胞簇间质面EMA表达阳性率为52.1%（38/73）.EMA＋组好发于胃（P=0.018）,EMA＋ 组阳性淋巴结平均数量为（6.6±5.8）枚,多于EMA-组（3.8±4.7）枚,两组差异具有统计学意义（P=0.029）,其余临床病理学参数EMA＋组与EMA-组比较差异无统计学意义.IMP3在EMA＋组GAMPD中的表达阳性率为86.8%（33/38）,显著高于普通腺癌（P＜0.05）.而E-cadherin在GAMPD中的阳性表达率则显著低于普通腺癌（P＜0.00）.结论 GAMPD是一种在组织学形态、免疫表型和生物学行为上不同于胃肠道普通腺癌的特殊类型,侵袭性强、预后差.免疫组织化学联合检测EMA、E-cadherin和IMP3的表达对GAMPD的病理诊断和预测预后有帮助.

Objective To study the clinicopathologic features and immunophenotype of gastrointestinal adenocarcinomas with a micropapillary pattern differentiation（GAMPD）. Methods Seventy-three eases of GAMPD arising in gastrointestinal tract were retrospectively reviewed.Immunohistochemical study for epithelial membrane antigen（EMA）, insulin-like growth factorⅡmRNAbinding protein-3（IMP3）and E-cadherin was performed.Results Amongst the 73 cases studied,the micropapillary pattern accounted for 5% to 70% of the tumor component.It was often seen in a background of moderately differentiated adenocarcinoma.As compared with conventional adenocarcinoma,nodal metastasis was more frequently observed and the TNM tumor stage was statistically higher in GAMPD.The occurrence of micropapillary component in metastatic lymph nodes positively correlated with the proportion of mieropapillary pattern in primary lesions.EMA staining on the stroma-facing surface of tumor micropapillae was demonstrated in 52.1%（38/73）of the cases.As compared with EMA-negative GAMPD, EMA-positive GAMPD was more in the stomach（P=0.018）.and with more metastatic lymph nodes（6.6 4-5.8 vs 3.8 ±4.7, P=0.029）.The rate of IMP3 expression in EMA-positive GAMPD was 86.8%（33/38）,which was higher than that in conventional adenocarcinoma.In contrast.the rate of E-cadherin expression in GAMPD was lower than that in conventional adenocarcinoma.Conclusions GAMPD is a distinctive variant of gastrointestinal adenocarcinomas and different from conventional adenocarcinoma in tumor morphology.immunophenotype and biologic behavior.It carries an aggressive clinical course and poor prognostic outcome.Immunohistochemical study for EMA.IMP3 and E-cadherin would be helpful in the diagnosis and prognostic evaluation of GAMPD.