Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a non-Hodgkin’s lymphoma which arises within and is confined to the central nervous system. For many years this tumor was called microglioma, reticulum cell sarcoma, or perivascular sarcoma, but the lymphocytic origin of the malignant cell which comprises this neoplasm is now well established 1–3. While it is clear that PCNSL is a malignant lymphocytic tumor, how and why a lymphoma develops within the CNS which lacks lymph nodes and lymphatics remains an unanswered question.