Lymphoma Related to the Ventricular System: A Rare Case Report and Systematic Review of Intraventricular Lymphomas.

Background: Intraventricular central nervous system (CNS) lymphoma is an atypical presentation of extranodal lymphoma, whether primary or secondary. The most commonly diagnosed subtype of lymphoma is diffuse large B-cell lymphoma (DLBCL). There is a documented relation of HIV, EBV and KSHV infections with lymphomagenesis. AIDS-related lymphomas (ARLs) are described as a defining illness of the acquired immunodeficiency syndrome (AIDS). This study presents a novel case and systematic review of clinical, radiographic and histopathological features of intraventricular lymphomas. Methods: We report on a 27-year-old woman with a left lateral ventricle DLBCL with surrounding edema treated with steroids. A systematic review of 147 additional cases (1977-2025) was conducted, analyzing patient demographics, tumor characteristics, clinical features, imaging, treatment, and outcomes. The tumor locations were divided into three groups depending on the extent of ventricular involvement. Descriptive statistics summarized findings. Findings: 147 cases (mean age, 54.2 years; range, 3-87; 63.3% male) were analyzed. Immunodeficiency in patients was unusual (6.1%). Fully intraventricular lesions were the most common presentation (52.4%), with systemic involvement solely in 10 cases (6.8%). The lesions were predominantly located in the lateral ventricles or fourth ventricles (46 times each), and bilateral involvement was noted 37 additional times. DLBCL was diagnosed in 101 cases (78.9%). Interpretation: Intraventricular involvement in central nervous system lymphoma poses a diagnostic and therapeutic challenge due to non-specific symptoms and atypical locations. Adding to the diagnostic difficulty of intraventricular masses in young patients, we wish to highlight that immunocompromised patients are a notably insignificant subgroup of patients in our study.