胃黏膜相关淋巴组织淋巴瘤的临床病理分析

Clinicopathological analysis of gastric mucosa-associated lymphoid tissue lymphoma

目的分析黏膜相关淋巴组织淋巴瘤（MALT淋巴瘤）的临床病理、免疫表型和基因重排特点，提高对该病的认识。方法回顾性分析1984年1月至2003年6月西南医院收治的35例胃MALT淋巴瘤患者的临床资料，对其病理检查标本进行病理形态学分型，采用免疫组织化学法测定其免疫表型和PCR方法检测其免疫球蛋白H（IgH）重链基因重排。应用χ^2检验和Mann-Whitney U检验分析结果。结果胃MALT淋巴瘤患者临床表现上腹不适、腹痛等消化道症状，没有特异性表现。40岁以上患者占74％（26／35）。32例为低分化，3例为高分化。31例为ⅠE期，2例为ⅡE1期，2例为Ⅳ期。病理检查结果发现胃MALT淋巴瘤细胞主要由中心细胞样细胞伴单核样B细胞或伴淋巴浆细胞组成。83％（29／35）的标本呈淋巴上皮样病变，6％（2／35）的标本有滤泡植入表现，33％（11／33）的标本有上皮下浆细胞浸润带。35例胃MALT淋巴瘤标本均为B细胞表型，19例有轻链限制性表达。16例Bcl-2呈阳性表达。增殖细胞核抗原在伴有转化的胃MALT淋巴瘤中呈高表达，提示伴有转化的胃MALT淋巴瘤增殖活性明显高于低度恶性者。33例IgH重链基因扩增出重排条带，阳性检出率为94％（33／35）。结论胃MALT淋巴瘤临床表现以消化道症状为主，发病率随年龄增加而升高，病理检查可以进行初步诊断，免疫组织化学检查可以进行鉴别诊断，IgH重链基因重排可以作为辅助检查。

Objective To analyze the clinicopathological characteristics, immunophenotypes and immunoglobulin heavy chain gene rearrangement of gastric mneosa-associated lymphoid tissue （MALT） lymphoma. Methods The clinical data of 35 patients with gastric MALT lymphoma who had been admitted to Southwest Hospital from January 1984 to June 2003 were retrospectively analyzed. The specimens of the gastric MALT lymphoma were obtained and their pathomorphological classifications were studied. The immunophenotypes and immunoglobulin heavy chain gene rearrangement were detected by immunohistochemistry and polymerase chain reaction, respectively. All the data were analyzed by chi-square test and Mann-Whitney U test. Results The main manifestations of patients with gastric MALT lymphoma were epigastric discomfort and abdominalgia. The percentage of patients with age≥40 accounted for 74% （26/35）. The gastric MALT lymphoma has low differentiation in 32 patients, and high differentiation in 3 patients. There were 31 patients in Ⅰ E stage, 2 in Ⅱ E1 stage and 2 in Ⅳ stage. Pathological examination showed that gastric MALT lymphoma was composed of centrocyte-like cells and mononuclear-like B cells or lymphoplasma cells. Twenty-nine specimens were with lymphoepithelial lesions （83%）, 2 with follicular colonization （6%）, and 11 with plasma cells segregated beneath the surface epithelium （33%）. All the 35 specimens were B call immunotype. Restrictive expression of κ and λ. light chains of the immunoglobulin was found in 19 cases, and Bcl-2 positive expression was found in 16 cases. High expression of proliferating cell nuclear antigen was found in gastric MALT lymphoma with transformed blasts, which indicated that gastric MALT lymphoma with transformed blasts was more active in proliferation than those of low grade. A monoclonal pattern of immunoglobulin heavy chain gene rearrangement was detected in 33 patients （94%）. Conclusions Digestive symptoms are the main manifestations of patients with gastric MALT lymphoma. The incidence of gastric MALT lymphoma increases with age. The final diagnosis of gastric MALT lymphoma depends on the pathological, immunohistochemical examination and laboratory test.