Background/Objectives: Diffuse large B-cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy, for which predicting clinical outcomes remains challenging. Although immune-checkpoint pathways are known to influence tumor biology, the impact of their germline variants on DLBCL susceptibility and prognosis has not been fully elucidated. Methods: Variants in PD-L1 gene CD274 (rs4143815, rs822336), and miR-155 gene MIR155HG (rs767649, rs1893650), assessed by TaqMan assays in 99 DLBCL patients and 113 age- and sex-matched healthy controls, were associated with clinicopathological features, treatment response, overall survival (OS), relapse-free survival (RFS), and disease susceptibility. Results: The PD-L1 variant rs822336 was significantly associated with relapse status (p = 0.005) and RFS (p = 0.008), with the wild-type GG genotype showing the poorest RFS that remained independent in the multivariate Cox analysis (HR = 2.387, p = 0.003). Conversely, rs4143815 showed a nominal association with treatment resistance (p = 0.026), while patients carrying the GG genotype had worse OS (p = 0.006). In susceptibility analyses, miR-155 variant rs767649 showed a nominal association with DLBCL risk, with the rare AA genotype showing an increased risk of DLBCL (OR = 5.234, p = 0.045), which did not remain significant after Bonferroni correction. Conclusions: In a hypothesis-generating manner, these findings suggest that PD-L1 genetic variants may predominantly influence disease progression and outcomes, while miR-155 variation may contribute to DLBCL susceptibility. These findings highlight germline immunogenetic variants as stable, treatment-independent markers that may inform future studies on risk stratification and prognosis in DLBCL.

Background: Enteropathy-associated T-cell lymphoma (EATL) is a rare subtype of mature T-cell lymphoma, accounting for fewer than 5% of peripheral T-cell lymphomas, with an aggressive course and poor prognosis. There are two types of this disease based on morphology and immunophenotype: type I, which is often, but not always, associated with celiac disease (classic EATL), and type 2, monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL). Risk factors for classic EATL are poor adherence to a gluten-free diet, advanced age, male sex, and HLA-DQ2 homozygosity. The treatment options include surgery and various chemotherapy regimens with autologous stem cell transplantation, but the outcomes are discouraging, and clinical trials with targeted and biologic therapies are needed. Case Presentation: We report three cases of type 1 EATL, all with lethal outcomes, with one patient dying during initial treatment, one dying following several surgical interventions and without waiting to start chemotherapy, and one dying following a good treatment response but with severe infection.