Primary central nervous system lymphoma involving entire ventricular system

Primary central nervous system lymphoma (PCNSL) is a rare tumor that accounts for <1%-4% of primary CNS tumor. [1] PCNSLs are class of non-Hodgkin's lymphomas which are primarily of diffuse large B-cell origin (90%), with remaining being T-cell lymphoma (10%). Author report a rare case of PCNSL presenting as an intracranial mass involving the entire ventricular system, in an immunocompetent 36-year-old male with severe headache, decreased vision, and unsteady gait. The diagnosis was obtained by histopathological and subsequent immunohistochemistry.