27th June 2023

Primary CNS lymphoma

CNS lymphoma is a rare, aggressive non-Hodgkin lymphoma and is an AIDS-defining malignancy. It is confined to the CNS and is usually associated with low CD4+ T-cells (<50 cells/ μL). It is strongly associated with Epstein-Barr virus infection in the context of HIV.

Presentations include:

• Focal neurological deficit
• Seizures
• Altered mental state/ behavioural change
• Features of raised intracranial pressure

Imaging is key to identifying primary CNS lymphoma. MRI with gadolinium contrast is the imaging technique of choice, which demonstrates multifocal necrotic lesions. This contrasts with primary CNS lymphoma in patients without HIV, which typically demonstrates a single lesion. Management typically involves antiretroviral therapy in addition to methotrexate. Rituximab is given on induction. CNS lymphoma with HIV has the worst prognosis of all HIV-related lymphomas.