摘要目的 探讨肝脏原发黏膜相关淋巴组织结外边缘区(MALT)淋巴瘤和肝脏假性淋巴瘤的临床病理特征、鉴别诊断.方法 收集2012年1月至2017年3月就诊于南京医科大学第一附属医院的3例肝脏原发MALT淋巴瘤和2例肝脏假性淋巴瘤患者资料,行HE和免疫组织化学EnVision法染色观察组织学形态,采用原位杂交法检测EB病毒编码小RNA,采用荧光原位杂交(FISH)技术检测MALT1基因,采用免疫球蛋白(Ig)基因重排检测技术分析克隆性基因重排情况,并复习相关文献.结果 3例MALT淋巴瘤,肿瘤结节状浸润汇管区,浸润及包绕周围肝组织并融合成结节或片状,多量小胆管陷入、散布其间伴淋巴上皮病变.瘤细胞围绕增生的淋巴滤泡,主要为中心细胞样和单核样B细胞,其中1例可见簇状上皮样组织细胞.瘤细胞CD20和PAX5阳性,不表达CD5、CD23、CD10、bcl-6及cyclin D1.2例肝脏假性淋巴瘤,病灶呈境界清楚的孤立性结节,其中1例可见部分纤维包膜.小胆管仅见于病灶周边,且缺乏淋巴上皮病变.淋巴组织增生以淋巴滤泡增生为主,缺乏明显异型性和单核样B细胞形态.免疫组织化学染色示增生的淋巴组织由B细胞和T细胞混合.Ig基因重排检测发现,3例肝脏原发MALT淋巴瘤呈单克隆性B细胞增生,而在2例假性淋巴瘤示多克隆性增生.FISH检测发现2例MALT淋巴瘤存在MALT1基因断裂.所有病例EBER原位杂交均为阴性.结论 肝脏原发MALT淋巴瘤和假性淋巴瘤均属肝脏罕见的淋巴组织增生性病变,两者具有重叠的组织学形态及免疫表型特征,互为首要鉴别诊断.综合分析组织形态、免疫表型和基因重排有助于区分两者.

abstractsObjective To study the clinicopathological features of primary hepatic extranodal marginal zone lymphoma of mucosa associated lymphoid tissue(MALT lymphoma)and hepatic pseudolymphoma, and to discuss their differential diagnosis, treatment and prognosis.Methods Three primary hepatic MALT lymphomas and two hepatic pseudolymphomas collected from January 2012 to March 2017 in the First Affiliated Hospital of Nanjing Medical University were evaluated by HE and immunohistochemistry(IHC),in-situ hybridization and immunoglobulin(Ig)gene rearrangement detection, and the relevant literature reviewed. Results In the three MALT lymphomas, tumor cells infiltrated the portal areas with nodular pattern, and invaded the surrounding normal liver with serpiginous configuration and formation of confluent sheets. A number of bile ducts were entrapped within the lesions, and showed lymphoepithelial lesion. Reactive lymphoid follicles were present and surrounded by tumor cells, consisting of predominantly centrocyte-like cells and monocytoid B cells. There were clusters of epithelioid histiocytes in one case. The tumor cells were positive for CD20, PAX5 and negative for CD5, CD23, CD10, bcl-6, and cyclin D1. In the two hepatic pseudolymphomas, the lesions presented as solitary nodules well-demarcated from the surrounding liver tissue; one case was partially encapsulated with fibrous tissue.Entrapped bile ducts were only found at the edge of the lesions without lymphoepithelial lesion. The lesions comprised of massive lymphoid proliferation consisting predominantly of reactive lymphoid follicles, but not monocytoid B-cells or atypical cells. By IHC, a mixture of B- and T-cell population was identified. A monoclonal rearrangement of the Ig gene was detected in all three MALT lymphomas but not in two pseudolymphomas. Interphase fluorescence in situ hybridiazation test for MALT1 break-apart gene was positive in two cases of MALT lymphomas and EBER was negative in all studied cases. Conclusions Primary heptic MALT lymphoma and pseudolymphoma are both rare lymphoid proliferative lesions of liver. These two lesions have overlapping histological and IHC features and are top differential diagnosis to each other. A combination analysis of morphology, immunophenotype and Ig gene rearrangement is helpful to distinguish between them.