Intraocular lymphoma

Intraocular lymphoma (IOL) is a rare tumor characterized by the presence of lymphomatous cells infiltrating different ocular structures, associated or not with concomitant lesions in other areas of the central nervous system (CNS) or in distant organs. Some studies suggest an increasing incidence of IOL in the last few decades, with a peak of incidence in the fifth and sixth decades of age. IOL frequently resembles uveitis at presentation and is often misdiagnosed. Most patients with IOL will develop parenchymal brain lesions, and intraocular infiltration can be detected during clinical staging in patients presenting with primary CNS lymphoma. IOL can be stratified on the basis of the ocular structures infiltrated: the vitreoretinal form is the most common presentation of IOL, while lymphomas arising in the iris or the choroid are less common forms, with particular clinical and histopathological characteristics. Extent of disease evaluation is the same as proposed for primary CNS lymphoma. The prognosis of IOL remains relatively poor. Therapeutic options range from radiotherapy to chemotherapy, using CNS active drugs, like methotrexate and cytarabine. Encouraging results with intravitreous administration of rituximab and methotrexate and high-dose chemotherapy supported by autologous stem cell transplantation have been described. This chapter is focused on molecular, histopathological, clinical, and biological features, as well as management and prognosis of the different forms of IOL.