There are two main types of intraocular lymphomas: primary central nervous system involvement (PCNSL) and primary central nervous system with ocular involvement (PCNSLO). The difference between PCNSL and PCNSLO is that PNSCL involves the central nervous system, while PCNSLO does not. 56-86% of orbital lymphomas are classified PCNSL and 15-25% are classified PCNSLO.
