Intraocular lymphoma (IOL) may be either primary (PIOL) or secondary (SIOL). Secondary intraocular lymphoma arises from a systemic lymphoma.
Types of secondary intraocular lymphoma:
(1) isolated (primary site present prior to SIOL)
(2) with systemic lesions
(3) with CNS lesions
Primary sites for secondary intraocular lymphomas:
(1) lymph node
(2) testis
(3) breast
(4) other
Histopathology of the lymphoma:
(1) 90% diffuse large B-cell lymphoma (most of ABC subtype)
(2) 5% intravascular lymphoma
(3) 5% NK or T cell