Detection Of Multiple Hit Diffuse Large B Cell Lymphoma And Investigation On Its Clinicopathological Features

Objective:Multiple hit diffuse large B cell lymphoma is a highly aggressive B-cell lymphoma named according to the characteristics of molecular genetics. For this tumor, the incidence rate is low, the clinical pathological characteristics are complex, and the prognosis is poor. Because of Multiple hit diffuse large B cell lymphoma has a good response to DA-EPOCH-R chemotherapy regimen, it is necessary to detect it in a timely manner to guide the clinical treatment.The study is aimed to detect Multiple hit diffuse large B cell lymphoma cases by the detection related protein of DLBCL samples and the combination of molecular genetic techniques, and then explore its clinical pathological characteristics.Methods:In this study,374 cases of DLBCL were collected from the files of Department of Pathologcal, Sichuan Provincial People’s Hospital. By two lymphoma experts selected and finally screened outto meet the experimental conditions in 348 cases. Pathological diagnosis was based on the latest version (2008) of hematopoieticand lymphoid neoplasms WHO classification. The expression of c-MYC, CD10, BCL-6, MUM-1, BCL-2, CD5, Ki-67 protein were detected by immunohistochemistry (IHC) according EnVision two-step process. Immunohistochemicaltyping reference Hans algorithm. FISH was performed in the cases with c-MYC protein positivecases. For the FISH positive cases, FISH of BCL-2 gene and BCL-6 gene should be done. Used small RNA in situ hybridization to detect EBV infection coding.Finally, clinical data and pathological data were collected and statistically analyzed.Results:1.The MHL screening results:(1) In 348 cases of DLBCL, c-MYC protein was positive in 178 cases (51.1%), BCL-2 protein was positive in 288 cases (82.8%), both c-MYC and BCL-2 protein were positive in 158 cases (45.4%), and BCL-6 protein was positive in 134 cases (38.5%). (2) Among 348 cases of DLBCL, MYC gene translocation was detected in 47 cases (13.5%) and single-hit lymphoma (SHL) was diagnosed in 6 cases (1.7%), double-hit lymphoma (DHL) in 36 cases (10.3%), triple-hit lymphoma (THL) in 5 cases (1.4%).2. Clinicopathological features of MHL:(1)The median age was 62 years old, and the age distribution was 19 to 82 years old in 47 cases of MHL patients. (2) Female patients were more than male, and the gender ratio was 1:1.25. (3) 25 cases (53.2%) were in lymph nodes and 22 cases (46.8%) were outside the lymph nodes. (4)Most (86.1%) patients at Arbor Ann clinical stage Ⅲ-Ⅳ,75% of the patients had high LDH levels in different degree,41.7% of the patients had B-symptoms, and 69.4% of the patients with international prognostic index (IPI) score of 3 to 5 points. (5)On histological type:39 cases (83%) were central blastic cell type,8 cases (17%) were immunoblastic cell type..(6) Immunohistochemistry:The expression of CD10, BCL-6 and Mum-1 was 44.7%,46.8% and 29.8%; Ki-67 index median percentage was 70%,38 cases were higher than 60%; Both c-MYC and BCL-2 were expressed in 46 cases (97.9%). (7) According to Hansalgorithm into GCB subtype and non-GCB subtype for 33 and 14 cases, GCB and non-GCB ratio was 2.36:1. (8) EBV in situ hybridization detection:EBER was positive expression in 18 cases (38.3%). (9) Treatment and Survival analysis:in the 36 patients with follow-up data,16 (44.5%) cases only underwent surgical resection,20 cases (55.5%) underwent surgery combined with CHOP, R-CHOP or DA-EPOCH-R regimen chemotherapy. Followe d up from 1 to 64 months, the median survival time was 6 ± 1.1 months, the average survival time was 11.5±2.1months,5 cases (13.9%) survived and 31 cases (86.1%)died.Conclusion:(1) MHL in DLBCL is a rare type of aggressive lymphoma with unique clinical significance. (2) IHC is the first effective tool for screening of MHL in the DLBCL, and FISH is the gold standard to verify MHL. IHC combined with FISH to detect MHL is simple and effective and suit for clinical survey. (3) MHL more in female, lymph nodes, Ann Arbor clinical stage III to IV, high levels of LDH, high IPI score, GCB type of Hans, Ki-67PI high, BCL-2 positive,EBV infection positive rate is relatively high. (4) Arbor Ann clinical stage, GCB subtype, BCL-2 positive expression and EBV positive infection are independent factors in patients with MHL. (5) Compared with non MHL, MHL patients with poor treatment effect and poor prognosis. (6) The prognosis of MHL is worse than that of DEL, and the prognosis of DEL is worse than that of non DEL patients.