"Quadruple-hit" primary testicular diffuse large B-cell lymphoma with MYD88 L265P mutation, IGH::MYC, and IRF4- and BCL6-rearrangements.

Classification of DLBCL relies on clinical, immunohistochemical, and genetic information. We report a case of primary testicular diffuse large B-cell lymphoma (PT-DLBCL) with a hitherto unreported constellation of pathologic findings to illustrate the challenges of DLBCL classification. A standard hematopathology workup was followed by gene expression profiling (GEP) to determine the DLBCL cell of origin (COO). A 75-year-old man presented with a unilateral testicular mass that had developed over the course of 1 month. Pathologic examination demonstrated involvement by DLBCL. Clinical staging revealed no systemic disease. Genetic testing showed an MYD88 mutation, as well as IGH::MYC and IRF4- and BCL6-rearrangements. Gene expression profiling demonstrated an activated B-cell expression profile. This case highlights the genetic complexity of DLBCL arising in the testis and questions the clinical significance of the identified genetic abnormalities.

The Mutation of BTG2 Gene Predicts a Poor Outcome in Primary Testicular Diffuse Large B-Cell Lymphoma.

Introduction: Primary testicular diffuse large B-cell lymphoma (PT-DLBCL) is a rare and aggressive form of mature B-cell lymphoma commonly found in elder males, but its genetic features are poorly understood. In this study, we had performed target-sequencing of 360 lymphoma-related genes on 76 PT-DLBCL patients with a median age of 65 (33-89). Our data provide a comprehensive understanding of the landscape of mutations in a small subset of PT-DLBCL. Methods: A total of 76 PT-DLBCL patients were sequenced, and their clinical data and follow-up data were collected. The relationship between mutated genes, clinical data and prognosis and survival of PT-DLBCL patients was retrospectively analyzed by statistical software. Results: We observed a median of 15 protein-altering variants per patient in our data and was identified recurrent oncogenic mutations of 360 lymphoma-related genes involved in PT-DLBCL, including PIM1 (74%), MYD88 (50%), KMT2D (38%), KMT2C (34%), BTG2 (34%), TBL1XR1 (34%) and ETV6 (24%). Compared with classic DLBCL, PT-DLBCL showed an increased mutation frequency of PIM1, MYD88, BTG2, while NOTCH1 appeared exclusive mutated with PIM1, MSH3 and ETV6. Cox risk model regression analysis showed that age ≥60 years, IPI 3-5 points, BTG2 gene mutation and extranodal organ invasion suggested poor prognosis. Finally, we constructed an OS predict model of PT-DLBCL patients using above factors with a high accuracy. Conclusion: In conclusion, our results revealed genomic characterization of PT-DLBCL, and the mutation of BTG2 was an independent factor predicting a poor prognosis.

Loss of 5-hydroxymethylcytosine as a Poor Prognostic Factor for Primary Testicular Diffuse Large B-cell Lymphoma.

Background: 5-Hydroxymethylcytosine (5-hmC), a stable epigenetic marker, is closely related to tumor staging, recurrence and survival, but the prognostic value of 5-hmC in primary testicular diffuse large B-cell lymphoma (PT-DLBCL) remains unclear. This study aimed to investigate the 5-hmC expression in PT-DLBCL and evaluate its prognostic value. Methods: A total of 34 patients with PT-DLBCL treated in the Department of Hematology from August 2000 to August 2020 were included in this study. The expression of 5-hmC in PT-DLBCL tissues and normal testicular tissues were assessed by immunohistochemistry. 5-hmC staining is estimated as a percentage under every nuclear staining intensity score (0-3), 0 or 1 of which were regarded as 5-hmC reduction. The quantification of 5-hmC reduction is defined as the percentage of cells with 5-hmC staining scores of 0 and 1. According 5-hmC reduction of 80%, a 5-hmC reduction of <80% is regarded as "5-hmC high-level group", and a 5-hmC reduction of ≥80% is regarded as "5-hmC low-level group". Furthermore, Cox regression model was used to evaluate the prognostic value of all covariates. Results: The median percentage of 5-hmC reduction in the PT-DLBCL group was 77.50% (60%-90%), the median 5-hmC reduction in the normal testicular tissues was 30% (20%-50%). Compared with normal testicular tissue, 5-hmC levels in PT-DLBCL tissue were significantly decreased (p<0.05). Of the 34 PT-DLBCL patients, 17 had tumors with relatively low 5-hmC expression (5-hmC reduction of ≥80%) and 17 had tumors with relatively high 5-hmC expression (5-hmC reduction of < 80%). 5-hmC expression was negatively correlated with international prognostic index (p = 0.037), while there was no significant difference in 5-hmC decrease among different groups of age at diagnosis, lactate dehydrogenase, testicular lymphoma involvement (unilateral or bilateral), Ki-67 and tumor diameter. Relatively low 5-hmC expression indicated shorter overall survival (OS) (5-year OS 50.2% vs 81.3%, p=0.022) and progression-free survival (PFS) (5-year PFS 38.5% vs 70.7%, p=0.001). Cox multivariate analysis of IPI (2-3 vs. 0-1), intrathecal prophylaxis (No vs. Yes), and 5-hmC reduction (≥80% vs. <80%) showed that 5-hmC reduction ≥80% (hazard ratio: 7.252, p = 0.005) and not receiving intrathecal prophylaxis (hazard ratio: 7.207, p =0.001) are independent risk factors for poor prognosis of PT-DLBCL. Conclusion: Our results suggested that 5-hmC decline can be identified as a poor prognostic predictor for PT-DLBCL. It is necessary to further explore the underlying mechanism of this epigenetic marker to identify methods to re-establish 5-hmC levels and provide new targets for cancer therapy.

Prognostic Significance of LDH Ratio in Serum/Cerebral Spinal Fluid of Patients with Primary Testicular Diffuse Large B-Cell Lymphoma.

OBJECTIVE: Primary testicular diffuse large B-cell lymphoma (PT-DLBCL) is relatively rare, and risk factors of this disease are still not well understood. This study aims to identify clinical features and prognostic factors of PT-DLBCL patients. METHODS: Thirty-two patients were included in this retrospective study who were diagnosed as PT-DLBCL and treated in Fudan University Shanghai Cancer Center between November 2010 and May 2018. The demographic details, clinico-pathological characteristics of the patients were summarized, and the impact on progression-free survival (PFS) and overall survival (OS) was analyzed. RESULTS: The median age of the patients was 57 (range 36-76) years old. All patients received rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) for 4-6 cycles and central nervous system (CNS) prophylaxis, with a CR rate 87.5% and an ORR 96.9%. Nineteen patients continued prophylactic contralateral testis radiation therapy (PCTRT) in our hospital. The 3-year PFS and OS rates were 79% and 92%, respectively. None of the 19 patients who received PCTRT experienced local recurrence. All three patients who suffered from CNS relapse were germinal center B-cell subtype. Kaplan-Meier analyses showed that PT-DLBCL patients with late-stage (Stage IV) (P =0.022), higher IPI score (IPI≥ 2) (P =0.017), B symptoms (P =0.004), and elevated LDH level (P =0.03) had a shorter PFS. More importantly, we found that patients with the ratio of the LDH level in serum to that in CSF ≥ 6.5 suffered from a worse PFS (P =0.028). CONCLUSION: Our work revealed that staging IV, IPI score ≥2, having B symptoms and elevated LDH level were risk factors for PT-DLBCL patients. Significantly, the PT-DLBCL patients with a high ratio of LDH level in serum to that in CSF were indicated to have a worse PFS.

Expression of programmed cell death-ligand 1 in primary testicular diffuse large B cell lymphoma: A retrospective study.

The present study evaluated programmed cell death-ligand 1 (PD-L1) expression in tumor cells and in the tumor microenvironment (TME) and its association with clinical data in primary testicular diffuse large B cell lymphoma (DLBCL). PD-L1 was determined by immunohistochemistry in 30 patients with primary testicular DLBCL and assessed for associations with clinical characteristics, progression-free survival (PFS) and overall survival (OS). The mean patient age was 62.2 years. Overall, 10 (33.3%) patients had advanced-stage (stage III/IV) disease and 14 (46.7%) patients had an International Prognostic Index (IPI) of ≥3. The median follow-up time following orchiectomy was 23.5 months. During this time, 10 (33.3%) patients experienced disease progression and 11 (36.7%) patients succumbed. PD-L1 expression in tumor cells and in the TME was detected in 20 (66.7%) and 13 (43.3%) patients, respectively. PD-L1 expression on tumor cells and in the TME was higher in those at an early stage compared with patients with an advanced stage of disease (P=0.045 and 0.017, respectively). In addition, PD-L1 expression in tumor cells was higher in patients with a low IPI compared with those with a high IPI (P=0.019). A Kaplan-Meier analysis identified no association of PD-L1 expression on tumor cells with PFS (P=0.763) or OS (P=0.531), or of PD-L1 expression in the TME with PFS (P=0.572) or OS (P=0.934). The present study demonstrated that PD-L1 expression in tumor cells and in the TME was higher in patients at an early stage of disease compared with those at an advanced stage, and that PD-L1 expression on tumor cells was higher in patients with a low IPI than in those with a high IPI. Furthermore, PD-L1 expression in tumor cells and in the TME was not associated with PFS or OS.

The pathobiology of primary testicular diffuse large B-cell lymphoma: Implications for novel therapies.

Primary testicular lymphomas (PTL) are the most prevalent type of testicular cancer arising in men over the age of 60. PTL accounts for approximately 1-2% of all non-Hodgkin lymphomas and most present with localized disease but despite this, outcome is poor. The majority of cases represent an extranodal manifestation of diffuse large B-cell lymphoma (DLBCL), known as primary testicular DLBCL (PT-DLBCL). Gene expression profiling has established that over 75% of PT-DLBCLs resemble the activated B-cell-like (ABC) or non-germinal center subtype of nodal DLBCL. In distilling the specific mutational landscape and immunophenotypic profiles, immune-escape and sustained signalling emerge as prominent features of PT-DLBCL. These include genomic alterations arising within the core components of antigen presentation (CIITA, B2M, and HLA loci) and structural rearrangements of programmed death ligands 1 (CD274) and 2 (PDCD1LG2). Enrichment for somatic mutations within NF-κB pathway genes (MYD88, CD79B, NFKBIZ, BCL10, and MALT1) also feature prominently in PT-DLBCL. Taken together, the unique molecular and clinical characteristics of PT-DLBCL have informed on aspects of the distinct disease biology of this organotypic lymphoma that may guide rational therapeutic strategies.

Expression and significance of EZH2 protein in primary testicular diffuse large B cell lymphoma / 临床与实验病理学杂志

Purpose To explore the expression and significance of histone methyltransferase EZH2,clinicopathological features in primary testicular diffuse large B-cell lymphoma (DLBCL).Methods Immunohistochemical of Ventana Ultra View two-step staining was used to detect expression of EZH2 in 17 cases of primary testicular DLBCL.The relationship between EZH2 expression and its clinicopathological features were analyzed.Sanger squencing was used to detect EZH2 Y641 mutation in these cases.Results Morphologically,the tumor cells resembled centroblasts in 11 cases,immunoblasts in 3 cases,and anaplastic variants in 3 cases.Immunophenotypically,14 cases were non-germinal centre B cell like (non-GCB) type and 3 cases were germinal centre B cell like (GCB) subtype.EZH2 overexpressed in all 17 cases.EZH2 overexpressed in nearly tumor celts with uniformly strong intensity in 15 cases,and more than 70％ tumor cells with moderate to strong intensity in 2 cases.The follow-up information was obtained in 9 patients,with a median survival time of 35 months.No association was found between the level of EZH2 expression and outcome of patients.No mutation of EZH2 Y641 was detected.Conclusion Primary testicular DLBCL is a rare aggressive B cell lymphoma with distinctive clinicopathological features.Detection of EZH2 expected to assist in the diagnosis and treatment of tumor.

CD79B and MyD88 gene mutation in primary testicular diffuse large B cell lymphoma / 临床与实验病理学杂志

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.