胃肠道B细胞性淋巴瘤形态学及免疫组织化学分析

Gastrointestinal B-cell lymphoma： a morphologic and immunohistochemical study of 194 cases

目的 探讨胃肠道B细胞淋巴瘤的分类特点及病理诊断.方法 对194例胃肠道B细胞淋巴瘤分别进行HE染色和免疫组织化学染色,临床病理学观察内容包括：患者性别、年龄、肿瘤发生部位、浸润深度、组织结构（淋巴上皮病变、反应性/残留淋巴滤泡、凝固性坏死/坏死碎片、结节状生长方式）.免疫组织化学染色采用EnVision二步法,每例标记9种抗体,包括：Pan B、Pan T、bcl-6、CD10、bcl-10、cyclin D1,末端脱氧核苷酸转移酶（TdT）、MUM1、Ki-67.结果 194例胃肠道B细胞淋巴瘤的男女之比为1.4∶1;发病年龄最小为8岁,最大为85岁.诊断为弥漫性大B细胞淋巴瘤（DLBBCL）128例（66.0%）,其中DLBCL伴黏膜相关淋巴组织边缘区B细胞淋巴瘤（MALT淋巴瘤）成分的有16例;MALT淋巴瘤40例（20.6%）;滤泡性淋巴瘤（FL）8例（4.1%）;淋巴浆细胞性淋巴瘤（LPL）5例（2.6%）;套细胞淋巴瘤（MCL）3例（1.6%）;B淋巴母细胞性淋巴瘤（B-LBL）1例（0.5%）;不能分型9例（4.6%,其中5例为活检标本）.发生于胃100例（51.5%）、小肠43例（22.2%）、回盲部26例（13.4%）、阑尾1例（0.5%）、结肠21例（10.8%）、直肠3例（1.6%）.163例手术切除标本中侵犯黏膜层20例（12.3%）、浅肌层20例（12.3%）、深肌层19例（11.6%）、全层104例（63.8%）.见有淋巴上皮病变、反应性/残留淋巴滤泡、凝固性坏死/坏死碎片、结节状生长改变者分别为52、29、66和30例.免疫组织化学标记,194例均表达CD20而不表达CD3,不同类型的淋巴瘤对bcl-6、CD10、bcl-10、cycin D1、TdT、MUM1、Ki-67有不同程度的表达.结论 胃肠道B细胞淋巴瘤主要分大B细胞性和小B细胞性两大类,小B细胞性淋巴瘤的分型是病理诊断的难点.对胃肠道B细胞淋巴瘤的诊断方法提出了建议路线.

Objective To study the morphologic and immunohistochemical features of gastrointestinal B-cell lymphomas. Methods One hundred and ninety-four cases of gastrointestinal B-cell lymphoma were retrieved from the archival file. The clinical features and pathologic findings were reviewed.Immunohistochemical study for B-cell markers, T-cell markers, bcl-6, CD10, bcl-10, cyclin D1, TdT,from 8 to 85 years. Amongst the 194 cases studied, 128 （66.0%） were diagnosed as diffuse large B-cell lymphoma, including 16 cases of large cell lymphoma associated with mucosa-associated lymphoid tissue （MALT） lymphoma component. There were also 40 cases （20.6%） of MALT lymphoma, 8 cases （4.1%）of follicular lymphoma, 5 cases of （2.6%） of lymphoplasmacytic lymphoma, 3 cases （ 1.6%） of mantle cell lymphoma, 1 case of （0.5% ） of B-lymphoblastic lymphoma and 9 cases （4. 6% ） of indefinite type （ including 5 biopsy cases）. The site of involvement included stomach （ 100 cases, 51.5% ）, small intestine （43 cases , 22.2% ） , ileocecal junction （ 26 cases , 13.4% ） , appendix （ 1 case , 0. 5% ） , colon （ 21 cases, 10.8%） and rectum （3 cases, 1.6%）. Amongst the 163 cases which had undergone surgical resection, 20 cases （12.3% ） cases had invasion down to the mucosa, 20 cases （12.3% ） down to the superficial muscular layer, 19 cases （ 11.6% ） down to the deep muscular layer and 104 cases （ 63.8% ）with full-thickness involvement. Histologic examination showed lymphoepithelial lesions in 52 cases, residual lymphoid follicles in 29 cases, coagulative necrosis in 66 cases and nodular growth pattern in 30 cases. The lymphoma cells in all cases were immunoreactive for B-cell marker CD20. There was also various degrees of positivity for bcl-6, CD10, bcl-10, cyclin D1, TdT, MUM1 and Ki-67. Conclusions Gastrointestinal B-cell lymphomas can be subdivided into two main groups： large B-cell lymphomas and small B-cell lymphomas. The latter group often poses diagnostic pitfalls. Accurate pathologic typing requires correlation with histologic and immunohistochemical findings.