How we diagnose and treat vitreoretinal lymphoma.

The eye is a rare site for the development of malignant lymphoma. Based on cell type and involved intraocular structures, which as a whole represent an immune-privileged site, several subtypes of primary intraocular lymphoma need to be discerned. Primary vitreoretinal lymphoma (PVRL), the most common form, is an aggressive B-cell malignancy and considered a subtype of primary central nervous system (CNS) lymphoma. Ocular symptoms are non-specific and often mimic uveitis, frequently resulting in delayed diagnosis. Bilateral ocular involvement and dissemination/relapse in the CNS are common. Diagnosis of PVRL is usually based on the analysis of vitreous biopsy material. In addition to cytological and immunocytochemical examination, measurements of cytokine levels and molecular determination of B-cell clonality and recurrent mutations increase the diagnostic yield. Both systemic chemotherapy and exclusively local treatment, including ocular radiotherapy and intravitreal chemotherapy, are successful approaches for the management of PVRL, although it is currently not predictable which patients require systemic treatment in order to avoid cerebral dissemination, a complication associated with a considerably worse prognosis.