Primary central nervous system lymphoma (PCNSL) is a rare malignancy that accounts for 2.5% of all brain tumors. This entity can involve the eyes and the entire central nervous system (CNS).
PCNSL presents with focal neurological deficits, neuropsychiatric symptoms, and increased intracranial pressure. Systemic symptoms are uncommon.
The initial diagnosis is based on brain magnetic resonance imaging (MRI) findings, and histological confirmation is needed via either vitreous biopsy, cerebral spinal fluid sampling (CSF), or a stereotactic brain biopsy.
Prognosis is highly dependent on patient age (>50 years) and performance status. Overall survival will vary and can be greater than 5 years for young patients with excellent performance status and less than 1 year for the elderly patients, with poor performance status.
PCNSL is a very radiation-sensitive malignancy; however, long-term survivors are rare in those who receive radiation alone. Great strides have been made with high-dose methotrexate (MTX)-based chemotherapy, with current median survival greater than 40 months.
Combination of MTX-based chemotherapy and whole-brain radiation therapy (WBRT) can yield devastating neurotoxicity, with some series reporting greater than 80% incidence in patients older than 60 years of age.
The current data for treatment are limited, with only two fully accrued randomized trial, and many heterogeneous phase II and retrospective series.
One recently presented abstract of a randomized trial of high dose MTX plus or minus WBRT demonstrated a benefit in progression free survival for WBRT but no overall survival benefit.
Current treatment trends include integration of newer chemotherapeutic/targeted agents with MTX-based chemotherapy and response-based indications for radiation therapy with possible dose de-escalation.