Brain Tumours

How to confirm the diagnosis

• Lumbar puncture: dissemination in the CSF in 20-30% of the patients with newly diagnosed PCNSL => Confirmation of a malignant B cell clone (FACS) or clonal IgH rearrangement using PCR • Stereotactic biopsy: do not administer steroids before! • Tumor resection does not affect survival – really…? Staging: • Slit lamp examination (ocular involvement in 10-15%) • CT scan chest and abdomen, bone marrow biopsy • HIV testing