Last Updated: March 12, 2020
Central nervous system (CNS) involvement with lymphoma is categorized into primary and secondary subtypes. These are vastly different clinical entities and therefore will be discussed separately in this chapter.
Primary CNS lymphoma (PCNSL) is an uncommon subtype of extranodal non-Hodgkin lymphoma involving the brain, leptomeninges, eyes, or spinal cord without systemic disease. PCNSL is seen annually in approximately 3% of patients diagnosed with primary brain tumors. These tumors represent about 1% of all non-Hodgkin Lymphomas and have an annual incidence of 0.47 per 100,000 person/year. PCNSL tends to present around 50-60 years of age in immunocompetent individuals and around 35 years of age in immunocompromised individuals.
Immunocompetence of the patient is a differentiating feature in PCNSL regarding the pathophysiology and prognosis. Immunodeficiency is the most significant risk factor for PCNSL, including HIV infection, congenital immunodeficiency, and medication-induced immunosuppression. Epstein-Barr virus is theorized to be a causal agent for development of PCNSL given its near universal presence in both immunocompromised and immunocompetent patients suffering from PCNSL. Although rarely observed, PCNSL can metastasize outside the neuroaxis.
Secondary CNS lymphoma (SCNSL) is most commonly observed in late-stage systemic lymphoma. Therefore, it often manifests as diffuse leptomeningeal disease along the neuroaxis. Given that...