From:  Isolated primary CNS lymphoma: a case report and a contemporary review

 Distinguishing features between PCNSL and SCNSL.

FeaturePCNSLSCNSL
OriginDe novo in CNSMetastatic from systemic lymphoma
Number of lesionsUsually solitary or a fewOften multiple
EnhancementHomogeneousMeningeal/Dural involvement is common
LocationDeep parenchymalLeptomeningeal, subependymal
Systemic diseaseAbsentPresent in staging (PET/BM biopsy)

PCNSL: primary central nervous system lymphoma; SCNSL: secondary central nervous system lymphoma; CNS: central nervous system.