Comparison of pathological features and prognosis between orbital and systemic diffuse large B cell lymphoma

Background Orbital diffuse large B cell lymphoma(DLBCL) is a kind of malignant lymphoma with higher morbidity,but the systematic study is difficult for the fewer cases and the lack of orbital DLBCL cell line.Objective This study was to compare the differences or similarities of histopathological characteristics between orbital DLBCL and systemic DLBCL,and to discuss whether systemic DLBCL cell line is available to in vitro research of orbit DLBCL.Methods The histopathological specimens were collected from 3 orbital DLBCL patients and 15 systemic DLBCL patients in Tianjin Eye Hospital and Tianjin Tumor Hospital from 2004 to 2009.The prognosis of the patients was followed-up,and the survival curve was drew.The histopathological examination of the specimens was performed using hematoxylin and eosin staining,and the expressions of CD20,CD79α,CD45RO,CD10,BCL-6,mum-1,Ki-67 and surviving in the specimens were detected by immunochemistry.The results mentioned above were analyzed and compared between orbital DLBCL and systemic DLBCL.Results The histopathological examination showed that the centroblastic type was the primary form in both orbital DLBCL and systemic DLBCL,according with the diagnosis of DLBCL.The differences in the positive expression rate of CD20,CD79α,CD45RO,Ki-67,survivin were not statistically significant between the two types of DLBCL (P =0.167,0.442,1.000,1.000,0.442).Immunochemistry revealed that 3 orbital DLBCL patients were germinal center B-cell-like (GCB),and 2 of the patients showed the positive expression for BCL-6 and mum-1 as well as absent expression for CD10,but the other patient presented the absent expression for BCL-6,mum-1 and CD10.In 15 systemic DLBCL patients,7 were GCB type,with the positive expression for CD10 in all the 7 patients and absent expression for BCL-6 in 6 patients.In addition,in 8 of non-GCB type,3 appeared to be absent expressed for CD10 and BCL-6,and 5 were positive expressed for BCL-6 and mum-1 and absent expressed for CD10.No significant difference was found in the survival duration between the orbital DLBCL and systemic DLBCL (P =0.067).Conclusions There exists no clinically significant difference in the pathological features,the expression of tumor cell markers and prognosis in both orbital and systemic DLBCL.These two DLBCLs appear to be similar in epidemiology and clinical staging,inferring that systemic DLBCL cell line is available in the in vitro study of orbital DLBCL. Key words: Neoplasm;  Orbit;  Diffuse large B cell lymphoma;  Pathology;  Immunochemistry