目的: 分析唾液腺干燥综合征(Sj?gren’s syndrome,SS)继发黏膜相关淋巴组织(mucosa associated lym-phoid tissue,MALT)淋巴瘤(SS-MALT淋巴瘤)的临床病理特点,并探索联合应用组织病理形态、蛋白表达和分子表型检测在唾液腺SS-MALT淋巴瘤病理诊断和预后评估中的应用价值。方法: 在1997年1月至2016年12月就诊于北京大学口腔医院并经病理确诊为唾液腺SS的260例患者中收集到16例SS-MALT淋巴瘤患者,另选取12例无唾液腺SS病史的MALT淋巴瘤(非SS-MALT淋巴瘤)患者作为对照,回顾性分析患者临床资料并随访。同时,应用苏木精-伊红染色、免疫组织化学、聚合酶链式反应(polymerase chain reaction,PCR)和荧光原位杂交技术(fluorescence in situ hybridization,FISH)观察组织病理变化,检测轻链限制性表达、免疫球蛋白(immunoglobulin,Ig)基因重排、染色体易位及基因异常,评价其在病理诊断和预后判断中的作用。结果: SS进展为MALT淋巴瘤的恶变率约为6.15%,恶变时间为3~240个月不等,其中有2例因发生高级别转化而死亡。SS-MALT淋巴瘤镜下表现为腺泡不同程度的萎缩破坏,以中心细胞样细胞为主的淋巴细胞弥漫浸润并破坏上皮岛。SS-MALT淋巴瘤组CD20和Pax5均为阳性(阳性率100%);Ki-67指数≤10%者占50%,>10%者占50%;AE1/AE3染色显示有残存腺上皮(93.75%)。全部病例肿瘤细胞CD3ε均为阴性,CD138染色显示有数量不等的浆细胞。37.5%的SS-MALT淋巴瘤患者检测到κ和λ轻链限制性表达。SS-MALT淋巴瘤组中免疫球蛋白重链(immunoglobulin heavy chain,IgH)-FR1、IgH-FR2、IgH-FR3、免疫球蛋白κ链(immunoglobulin kappa chain,IgK)-A、IgK-B的阳性检出率分别为33.3%、53.3%、33.3%、20.0%、26.7%,联合应用IgH和IgK的阳性检出率达93.3%。MALT1双色分离探针阳性率36.4%,IGH双色分离探针阳性率27.3%,BCL6双色分离探针阳性率27.3%;三种探针共同使用的基因异常检出率为72.7%。结论: 唾液腺SS-MALT淋巴瘤的病理诊断缺乏特异性的组织形态特点和蛋白表型,联合应用组织形态观察、免疫组织化学、PCR和FISH技术有助于该疾病的精准病理诊断。同时,虽然SS-MALT淋巴瘤一般被认为是惰性淋巴瘤,预后较好,但也应定期复诊和长期随访,以便早发现复发和高级别化的线索,提高患者的生存率。

Objective: To analyze the clinicopathological characteristics of mucosa associated lymphoid tissue (MALT) lymphoma secondary to Sj?gren’s syndrome (SS) (SS-MALT lymphoma) in salivary gland and to explore the value of the combined application of histopathological morphology, protein expression and molecular phenotype in pathological diagnosis and prognostic evaluation of SS-MALT lymphoma.Methods: Sixteen patients with SS-MALT lymphoma were collected from 260 patients who were diagnosed with SS in Peking University School and Hospital of Stomatology from January 1997 to December 2016. Twelve patients with non-MALT lymphoma secondary to SS (non-SS-MALT lymphoma) in salivary gland were selected as controls. The clinical data of the patients were retrospectively reviewed and analyzed. All the patients were followed up until December 20, 2019. Hematoxylin-eosin staining, immunohistochemistry, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques were used to observe the histologic characteristics and to detect the manifestations of light chain restrictive expression, immunoglobulin (Ig) gene clonal rearrangement, chromosome translocation and gene abnormality, so as to evaluate their values in pathological diagnosis and prognostic evaluation.Results: The malignant transformation rate of SS to MALT lymphoma was about 6.15%, ranged from 3 to 240 months, during which 2 patients died due to high-level deterioration. Microscopically, the acini of the glandular tissue were atrophied and destroyed. The tumor cells dominated by central cell-like lymphocytes grew diffusely, destroying the epithelial islands. All SS-MALT lymphoma cases were positive in CD20 and Pax5. Half of them had the Ki-67 proliferation index of 10% or less, and half greater than 10%. 93.75% cases expressed AE1/AE3 protein, which showed the residual glandular epithelium. All the tumor cells were negative in CD3ε, and the plasma cells were detected by CD138 antigen. The light chain restrictive expression of κ and λ was 37.5% in SS-MALT lymphoma group. The positive detection rates of immunoglobulin heavy chain (IgH)-FR1, IgH-FR2, IgH-FR3, immunoglobulin kappa chain (IgK)-A, and IgK-B in SS-MALT lymphoma group were 33.3%, 53.3%, 33.3%, 20.0%, and 26.7%, respectively, and 93.3% when together used with IgH and IgK. The positive rates of the MALT1, IGH and BCL6 genes with dual color break-apart probes were 36.4%, 27.3% and 27.3%, and the detection rate of chromosome translocation and gene abnormality by applying the three probes was 72.7%.Conclusion: There are no specific histological characteristics and protein phenotypes in the histologic diagnosis of SS-MALT lymphoma in salivary gland. The combined application of histopathological manifestations, immunohistochemistry, PCR and FISH techniques helps the accurate pathologic diagnosis of the disease. Although SS-MALT lymphoma is considered as an indolent lymphoma with a relatively favorable prognosis, the regular return visit and long-term follow-up should be conducted to detect the clues of recurrence and advanced deterioration.