CNS lymphoma

Epidemiology
About 3% of primary brain tumors
Incidence has increased over the past 20 years, probably secondary to aging population, increased incidence of immune suppressed patients (AIDS, transplants, etc)

Risk factors
Age greater than 60
Immune deficiency (HIV+ patients have tremendously increased risk for this disease)

Pathology
Over 90% of primary CNS lymphoma is diffuse large B cell type

Clinical
Most common presenting symptom is focal neurologic deficit
16 to 40% of patients have meningeal involvement
20% have ocular involvement

Staging
Brain MRI
LP
Ophthalmologic evaluation
CT of chest/abdomen/pelvis
Bone marrow biopsy
Bloodwork: CBC. CMP, LDH, HIV status

Imaging
Classic lesion is periventricular, brightly enhancing, diffuse
Most lesions are supratentorial

Prognostic factors
Age (older than 60 is worse)
PS (worse than 1)
Increased LDH
Increased CSF protein

Therapy
Avoid steroids before biopsy if possible
No benefit to debulking surgery
Current standard: high dose methotrexate; WBRT for salvage
High rates of neurotoxicity, especially in older patients