Primary Brain Lymphomas By Mark H Bilsky, MD, Weill Medical College of Cornell University Reviewed / Revised May 2023 View Patient Education Diagnosis Treatment Primary brain lymphomas, a type of primary central nervous system lymphoma, originate in neural tissue and are usually B-cell tumors. Diagnosis requires neuroimaging and sometimes cerebrospinal fluid analysis (including Epstein-Barr titers) or brain biopsy.