RT Journal Article SR Electronic T1 Primary central nervous system plasmablastic lymphoma in an HIV-positive patient JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e226755 DO 10.1136/bcr-2018-226755 VO 12 IS 3 A1 Ruben Rhoades A1 Jerald Gong A1 Neil Palmisiano A1 Onder Alpdogan YR 2019 UL http://casereports.bmj.com/content/12/3/e226755.abstract AB Plasmablastic lymphoma (PBL) is a rare subtype of diffuse large B-cell lymphoma, highly associated with HIV and Epstein-Barr virus (EBV) infections. It commonly presents in extranodal sites, often an oral mass, but reports of primary central nervous system PBL (PCNSPBL) are exceedingly rare. Here, we report on a 33-year-old man with newly diagnosed HIV infection who presented with acute-onset unilateral visual disturbance and was found to have biopsy-proven PCNSPBL. The neoplastic cells displayed a plasmacytoid appearance, with the expression of CD38 and CD138, and were positive for EBV by in situ hybridisation for EBV-encoded RNA. Systemic workup revealed the presence of Kaposi sarcoma, but no evidence of lymphoma. He is currently being treated with high-dose methotrexate, as well as antiretroviral therapy for his HIV infection, and has achieved a complete response.