Answer : B Systemic staging
Systemic staging is warranted prior to treatment because 4% to 12% of patients thought to have primary central nervous system lymphoma are found with systemic disease.
Primary central nervous system lymphoma comprises 5% of all primary brain tumors and 1% of non-Hodgkin lymphomas. The most common subtype is the diffuse large B cell variant.
Magnetic resonance imaging often shows hypointense lesions on T1, that are hyperintense on T2 with restricted diffusion on diffusion-weighted imaging. Post-contrast enhancement is typical. Up to 60% of lesions are solitary in immunocompetent individuals, while 30% to 80% of immunosuppressed patients present with multiple lesions.
Males are more frequently affected than females in immunocompetent individuals as well as in patients with AIDS. Lesions have a predilection for the periventricular white matter, as well as the frontal lobe and basal ganglia.