ABSTRACT
Objective:To analyze the clinical features and mutation of myeloid differentiation factor 88 (MYD88) L265P in patients with diffuse large B-cell lymphoma (DLBCL) of central nervous system (CNS).Methods:The clinicopathological materials of 45 cases of DLBCL of CNS were retrospectively collected in Xuanwu Hospital, Capital Medical University from September 2014 to February 2017. The clinicopathological data were retrospectively analyzed, combined with immunohistochemistry, EB virus in situ hybridization, imaging and medical history. The mutation of MYD88 L265P gene was detected by pyrosequencing and its clinical significance was analyzed. Results:The age of the patients ranged from 42 to 82 years [(57.6±8.8) years], including 24 males and 21 females. Totally 93.3% (42/45) of the patients had supratentorial tumours, which were single or multiple. The cerebral hemisphere (31/45, 68.9%) was the most common involved site, and 21 cases (21/45, 46.7%) had multiple lesions. Histologically, DLBCL in the CNS showed diffuse infiltration of tumor tissue, some of which grew around blood vessels in a "sleeve" arrangement. CD 20 and CD 79a were diffusely and strongly positive. Thirty-nine cases (39/45, 86.7%) were non-germinal center B cell (non-GCB) subtype and 6 cases (6/45, 13.3%) were germinal center B cell (GCB) subtype. MYD88 L265P mutation was found in 64.4% (29/45) patients. There was statistically significant difference between non-GCB type (71.8%, 28/39) and GCB type DLBCL (1/6, P=0.017). Compared with the operation/biopsy group without chemotherapy, operation+chemotherapy, biopsy+chemotherapy, operation/biopsy+chemotherapy+stem cell transplantation can improve the survival and prognosis ( HR=0.05, 95% CI 0.01-0.33 , P=0.002; HR=0.04, 95% CI 0.01-0.36 , P=0.004; HR=0.01, 95% CI 0.00-0.17 , P=0.001; respectively). Conclusions:DLBCL of the CNS is aggressive tumor with poor prognosis, the clinical manifestations are complex and diverse, and the diagnosis is challenging. MYD88 L265P is a common and specific gene mutation in primary CNS lymphoma(PCNSL), which is of great significance in the diagnosis and treatment of lymphoma. The MYD88 L265P mutation was more frequently detected in non-GCB than GCB subtype. Chemotherapy can improve the survival rate of PCNSL patients. If chemotherapy achieves complete remission and autologous hematopoietic stem cell transplantation is performed, there may be a chance of long-term survival.
ABSTRACT
Purpose To explore the mutation of CD79B and MyD88 in primary testicular diffuse large B cell lymphoma and their significance.Methods Histopathologic features were observed in 15 cases of primary testicular diffuse large B cell lymphoma and immunophenotype was analyzed by immunohistochemical staining (IHC).Sanger sequencing was used to detect CD79B Y196 and MyD88 L265 mutation in these cases.The relationship between CD79B,MyD88 mutation and the clinicopathological features was analyzed.Results Immunophenotypically,15 cases were non germinal center B cell type.CD79B (Y196) mutation was detected in 4 cases (26.7％).For MyD88,L265 mutation was found in 7 cases (46.7％).CD79B and MyD88 mutations were found in 3 cases.The followup information was obtained in 8 patients.No association was found between CD79B,MyD88 mutation and outcome of patients.Conclusion Primary testicular diffuse large B cell lymphoma of non germinal center B cell type is a rare aggressive B cell lymphoma with poor prognosis and poor response to chemotherapy.CD79B,MyD88 gene mnutation was detected in Chinese patients with frequency of 26.7％ and 46.7％ respectively.It is possible for molecular targeted therapy of the primary testicular diffuse large B cell lymphoma on the basis of high frequency of CD79B and MyD88 gene mutation.