Splenic Non-Hodgkin Lymphoma: A Clinicopathologic And Immunohistochemical Study

Background and Objective Splenic lymphoma may be primary or secondary, and the former was uncommon. In the splenic non-Hodgkin lymphoma, B-cell neoplasms were more common than T and NK-cell neoplasms. A retrospective study of clinicopathology was made for 70 cases of splenic NHL with immunophnotype analysis, detection of Epstein Barr virus infection and TCR-γgene rearrangement. The purpose was to investigate the clinical and pathologic features, pathologic diagnosis and differential diagnosis of the tumor. Statistic analysis was used for evaluation of prognosis related factors of the tumor.Materials and Methods 70 cases of splenic NHL were selected from the files of Pathology Department, West China Hospital of Sichuan University in period of Jan 1990 to Feb 2007. Related clinical data were collected and follow up was performed for all of the cases. Statistics was used for survival analysis of the tumors. Pathologic diagnosis was according to the WHO classification for tumors of hematopoietic and lymphoid tissue (2001). Immunophenotype analysis was performed by SP method. Antibodies selected included CD3, CD3ε, CD4, CD5, CD8, CD10, CD20, CD23, CD30, GD43, CD45RO, CD56, CD79a, Bcl-2, Bcl-6, TIA-1, granzymeB, PC, Ki-67, CyclinDl, MUM1, TdT and ALK-1. ISH and PCR were used for detection of EBER and TCR-γgene rearrangement respectively.Results (l)There were 60 cases(85.7%) of B-cell neoplasms, in which the main histological types were DLBCL(50%) and SMZL(23.3%). There were 32 cases(53.3%)confines to the diagnosis of primary splenic lymphoma. The other 10 cases(14.3%) were T and NK-cell neoplasms, in which the main histological types were HSTCL and ENK/TCL-N. (2)Splenic B-cell neoplasms were common in elder men, and the peak age of onset was about 50 years old. Clinically, patients always presented with splenomegaly or related discomfort. About 50% patients were in stageⅢand 30% patients had B symptoms when diagnosis. All the cases had obvious splenomegaly and mass lesion, such as big solitary nodule, multiple nodules with various size or diffusely distributed small nodules. The histological types of tumors were related to the gross features of the spleen. In DLBCL, 44.4% arised from germinal center B-cells, and 40.7% arised from activated B-cells. (3)Splenic T and NK-cell neoplasms were common in young and middle-aged people(mean35y). The course of disease was short. 70% patients were in stageⅢand 80% patients had B symptoms when diagnosis. All the cases had obvious splenomegaly, but mass lesion was seen in only one case. (4)Monovariate statistic analysis showed that age, clinical stage and B symptoms were related to the prognosis. B-cell neoplasms had better prognosis than T and NK-cell neoplams. With or without chemotherapy after splenectomy was not related to the prognosis.Conclusions Splenic NHL shows some features in clinical manifestations and pathology according to the histological types. The diagnosis of splenic B-cell neoplasms could be established basing on morphology and immunophenotype analysis in most of conditions. Occasionally, the detection of TCR-γgene rearrangement will help to make the diagnosis of splenic T and NK-cell neoplasms.