脾弥漫性红髓小B细胞淋巴瘤临床病理学特征

Clinicopathologic features of splenic diffuse red pulp small B-cell lymphoma

目的探讨脾弥漫性红髓小B细胞淋巴瘤(SDRPSBL)的临床病理学特征,诊断及鉴别诊断。方法收集2014-03—2016-08北京大学人民医院病理科诊断的SDRPSBL 2例,按WHO(2008)淋巴造血组织肿瘤分类和WHO(2016)更新内容,应用光镜观察、免疫组化染色,结合临床相关检查进行临床病理学分析,并复习相关文献。结果例1:女性,51岁,表现为贫血,淋巴细胞减低。例2:男性,40岁,淋巴细胞升高,LDH升高。2例均表现为白细胞升高,脾肿大,行脾切除术。镜下:脾红髓、白髓结构不清楚,可见弥漫浸润的淋巴样细胞,细胞小~中等大小,沿窦隙及窦索浸润,可见广泛出血,血湖形成。免疫组化染色:CD20和PAX-5(+),CD3、CD5、CD23(未见FDC网)、Cyclin D1、CD38和CD25均(-),Ki-67(5%,10%)。例1失访,例2一般状况良好。结论 SDRPSBL是一种独特的病种,病例少见,以小~中等大淋巴细胞弥漫性浸润脾红髓为主要特征,形态学及免疫表型不同于其他脾B细胞淋巴瘤。

Purpose To study the clinicopathologic features,diagnosis and differential diagnosis of splenic diffuse red pulp small B-cell lymphoma（ SDRPSBL）. Methods Two cases of SDRPSBL were selected from Peking University People＇s Hospital from 2014 to 2016. According to WHO classification of tumours of haematopoietic and lymphoid tissues in 2008 and updated of WHO classification in 2016,the cases were studied by microscopy,immunohistochemistry and clinical examinitions,with review of the related literature. Results Case 1 was female and 51 years old,presented as anemia and lymphocytopenia. Case 2 was male and 40 years old,presented as lymphocytosis and elevation of LDH. Both cases presented as elevation of WBC counting and splenomegaly,and splenectomy were performed. Microscopically,the structure of red pulp and white pulp of spleen was unclear,with intrasinusoidal infiltration of small to medium-sized lymphocytes in the spleen. Widespread bleeding and lake of blood can be seen. Immunophenotype showed that the tumor cells were positive for CD20,PAX5,and negative for CD3,CD5,CD23,cyclin D1,CD38,CD25; the proliferative index were 5% and 10%,respectively. Follow-up of Case 1 was lost,and general condition of Case 2 was good. Conclusion SDRPSBL is a distinct and rare entity,which is characterized by small to medium-sized lymphocytes infiltration in splenic red pulp. Differetial diagnosis from other small B cell lymphomas of the spleen is necessary.