Background: Mediastinal gray zone lymphoma (MGZL) is a rare B-cell lymphoma characterized by overlapping clinicopathologic and molecular features of primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (CHL). Under current WHO-HEMA5 and International Consensus Classification (ICC) frameworks, MGZL is restricted to EBV-negative lymphomas arising in the mediastinum. Methods: This review summarizes current evidence on epidemiology, clinical presentation, pathology, molecular characteristics, diagnostic challenges, and therapeutic approaches to MGZL, with data derived from retrospective series, limited prospective cohorts, and recent molecular studies. Results: MGZL predominantly affects young adults and commonly presents with bulky mediastinal disease. Diagnosis is challenging due to transitional morphology, pleomorphic Reed–Sternberg-like cells, and variable expression of B-cell and activation markers. Molecular studies demonstrate shared alterations with PMBL and CHL, including 9p24.1 (JAK2/PD-L1/PD-L2) gains, while additional reported features such as HOXA5 hypomethylation and MYC copy number gains support its biological distinctiveness, although evidence remains limited. Frontline treatment commonly involves intensive chemoimmunotherapy regimens such as DA-EPOCH-R; however, outcomes remain inferior to PMBL and CHL, with 5-year overall survival rates of approximately 40–60%. Relapsed or refractory disease frequently requires salvage chemotherapy and autologous stem cell transplantation. Immune-based therapies, including brentuximab vedotin and PD-1 inhibitors, have shown promising activity, particularly in combination. Conclusions: MGZL remains a diagnostically challenging and therapeutically complex lymphoma with inferior outcomes compared with related mediastinal lymphomas. Advances in molecular profiling and immunotherapy offer promising avenues toward more personalized treatment; however, prospective clinical trials and international collaboration are urgently needed to establish evidence-based management strategies for this rare entity.

Objective: Immunocompromised hosts (ICH) are at a higher risk of severe infections and mortality. This study aimed to examine the clinical manifestations and outcomes of ICH who were admitted to the hospital for COVID-19. Method: A total of 384 patients (mean age 61.515.9 y, 168 female) who were hospitalized between March 2020 and December 2020 were included in the study. These patients were examined in three groups: the ICH (n=40), comorbid patients (n=101), and the control group comprising immunocompetent patients without any comorbidities (n=243). All clinical and laboratory data were retrieved from the electronic hospital records and compared between the three groups retrospectively. Results: The mean age was 61.215.0 for ICH, 66.112.3 for comorbid, and 59.617.0 for control groups (p=0.003). We found that the mean leukocyte and neutrophil counts, C-reactive protein (CRP), ferritin, and D-Dimer levels were significantly higher and the albumin level was lower in ICH compared to the other two groups (p

Background: Mediastinal gray zone lymphoma (MGZL) is a rare B-cell lymphoma which shares clinicopathologic and molecular features between primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (CHL). Although included as provisional disease entity back in 2008 WHO classification after initial description in 1998, the concept of MGZL has since evolved, with latest WHO-HEMA5 and ICC limiting the entity to EBV-negative mediastinal lesion. Methods: This review summarizes the historical evolution, epidemiology, clinicopathologic characteristics, immunophenotypic and genetic features, diagnostic challenges, and therapeutic strategies for MGZL. Data from retrospective series, prospective cohorts, and recent molecular studies are synthesized to provide a comprehensive perspective. Results: MGZL generally affects young adults, especially males, and presents with bulky mediastinal disease. Transitional morphology, pleomorphic Reed–Sternberg–like cells, and variable B-cell and activation markers make its diagnosis challenging. Molecular studies have shown that they share changes with PMBL and CHL such as 9p24. 1 (JAK2/PD-L1/PD-L2); however, specific alterations, including HOXA5 hypomethylation and MYC gains, argue for its designation as a separate entity. Therapeutically, DA-EPOCH-R is one of the most effective regimens, but prognosis is still worse than PMBL or CHL, 5-year OS ~40–60%. Salvage chemotherapy and autologous transplantation are frequently necessary for relapsed/refractory disease. Novel therapies, especially brentuximab vedotin and PD-1 inhibitors, appear to be effective, especially in combination. Conclusion: MGZL continues to be a diagnostically challenging, and therapeutically complex lymphoma with an inferior prognosis compared to related entities. Advancements in molecular profiling and immunotherapy suggest the promise of personalized therapy. Yet, prospective clinical trials and international cooperation are urgently needed to develop guidelines for therapy of this rare lymphoma.