[Primary vitreoretinal lymphoma]

Primary vitreoretinal lymphoma (PVRL) is the most common intraocular lymphoma. It is a high grade malignant B‑cell lymphoma, which is thought to arise in the retina. It often infiltrates the central nervous system (CNS) and is therefore associated with a poor prognosis. The PVRL must be differentiated from other forms of intraocular lymphoma, such as the low-grade B‑cell lymphoma that rarely arises in the choroid. The choroidal lymphomas do not spread to the brain, they can be treated with low-dose external beam radiotherapy and the patients have a good prognosis. Since PVRL is a relatively rare tumor, there is little information with respect to its true incidence, to any geographical or ethnic variability and to the main risk factors apart from an association with immunosuppression, as a result of HIV or Epstein-Barr virus infections. The treatment of PVRL is very variable between oncology centres and is also dependent on the unilaterality or bilaterality of disease and whether there is any concomitant CNS involvement. Further studies and research projects in this field are necessary in order to diagnose PVRL at an early stage and to develop new targeted individualized treatment.