Primary CNS Lymphoma Arising from the 4thVentricle: A CaseReport and Review of the Literature

A 65-year-old male with a history of ischemic strokes, seizures, and subarachnoid hemorrhage presented with a 4-weekhistory of progressive diplopia, vertigo, nausea, and vomiting. Magnetic resonance imaging (MRI) revealed a25×18×17cmposterior fossa mass arising from the roof of the 4thventricle extending into the cerebellar vermis. Posterior fossacraniotomy with stereotactic biopsy confirmed a locally invasive diffuse large B-cell lymphoma (DLBCL). Primary centralnervous system lymphoma (PCNSL) arising from the 4thventricle is a rare extranodal manifestation of non-Hodgkinlymphoma (NHL), with few cases documented in the literature. Review of available cases lends support that lymphomaarising from the 4thventricle has a variable clinical presentation, occurs most commonly in immunocompetent males, andshould be on the differential of any immunocompetent adult presenting with a posterior fossa mass. Optimal treatmentmodalities are based largely on phase 2 clinical trials, and recommended guidelines regardless of anatomic location shouldbe adhered to.