TABLE 4.

Comparison of radiologic and clinical characteristics between low-grade and high-grade PCNSL in immunocompetent patients

Low-Grade PCNSL	High-Grade PCNSL
Radiological morphology
Moderate and inhomogeneous or absent contrast enhancement frequent	Usually strong and homogemeous contrast enhancement
Localization of lesions often without contact to subarachnoid space	Lesions typically in contact with the subarachnoid space
Hyperintensity of T2-weighted images often present	Hyperintensity on T2-weighted images possible
Location in deep brain structures and spine common	Location in deep brain structures and spine possible but infrequent
Clinical characteristics
Indolent clinical course possible	Aggressive clinical course almost invariably seen
Delays in diagnosis establishment possible due to paucity of symptoms and variable radiologic appearance	Diagnosis establishment usually rapid due to severe symptoms and typical radiological appearance
Long survival with absence of complete tumor remission possible	Survival without complete remission usually short
Long survival after local treatment (surgery, local radiotherapy) possible	Survival with local treatment short, whole brain treatment required

Note.—PCNSL indicates primary central nervous system lymphoma.