When location meets biology: combined risk patterns drive outcomes in primary central nervous system lymphoma

Aim: Primary central nervous system lymphoma (PCNSL) is a rare and aggressive extranodal lymphoma. Despite therapeutic advances, data from immunocompetent patients in real-world cohorts remain limited, and prognostic factors are still not clearly defined- especially in small retrospective series. Material and Methods: We retrospectively analyzed 19 immunocompetent patients diagnosed with PCNSL between June 2002 and March 2022 at a single tertiary oncology center. Clinical, radiological, pathological, and treatment-related parameters were collected. Overall survival (OS) was assessed, and univariate analysis was conducted to explore potential prognostic factors. Results: The median age was 49.1 years, and 57.9% were male. Focal neurological deficits were the most common presenting symptom. Poor outcomes were observed in patients with deep brain involvement, parietal lobe lesions, bilateral or multifocal disease, and germinal center B-cell (GCB) subtype. All GCB patients experienced relapse and died, while most non-GCB patients remained alive and disease-free. The Memorial Sloan Kettering Cancer Center (MSKCC) score effectively stratified risk groups. Median OS was 13.6 months. Multivariate analysis was not feasible due to overlapping high-risk features, limiting statistical independence. Conclusion: This study emphasizes the prognostic impact of combined anatomical and molecular risk factors in PCNSL and contributes real-world data from an underrepresented population. These findings may support the development of risk-adapted therapeutic strategies for this rare malignancy.