IntroductionLymphoproliferations of the eye, including intraocular and ocular adnexal non-Hodgkin lymphoma (NHL), constitute a heterogeneous group of neoplasms that represent less than 1% of all NHLs 1 and 5% to 15% of all extranodal sites. 2 First described in 1952, 3 they are the most frequent malignant tumors of the eye and ocular adnexae; in fact, in the Florida cancer registry, they represent up to 55% of all orbital tumors. 4 As for all NHLs, a marked increase of the incidence of ocular adnexal NHL has also been observed. 4 The clinical features and natural history of ocular adnexal lymphoma (OAL) is completely different from those of intraocular lymphoma, which emphasizes the need to distinguish between the therapeutic management of both. Intraocular lymphoma is a subset of primary central nervous system lymphoma, 5-7 and intraocular involvement is found in approximately 15% of affected patients. 8 The histologic subtype of intraocular lymphoma is almost always high grade 9,10 and it can occur in the context ofAIDS-related lymphoproliferations. In contrast, OALs-including lesions of the conjunctiva, lacrimal gland, orbit, and eyelids-are mainly low-grade tumors not associated with HIV infection. 11 Although combination chemotherapy with highdose methotrexate is the basis of treatment of primary central nervous system and intraocular lymphomas, 10,12 radiotherapy has been the standard treatment for low-grade ophthalmologic lymphomas. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] However, other treatment options, such as therapy with monoclonal anti-CD20 antibody, 31,32 may constitute a promising alternative to external beam irradiation and its potential toxicity. In addition, some reports have suggested a possible value of anti-Chlamydia psittaci antibiotic therapy. 33,34 In this review, which is exclusively focused on ophthalmologic lymphomas, we first present the pathologic, clinical, and prognostic factors of these lymphomas and then discuss all available treatment options in terms of safety and efficacy and their respective indications.
Biology of ophthalmologic lymphomas
Diagnosis of OALAs for all other forms of nodal and extranodal NHL, confirming a positive diagnosis of OAL is often long and difficult because the tumor is very small in most patients. Positive diagnosis must be based on histologic examination of a sufficient tumor sample obtained by surgical biopsy that is large enough to allow rigorous definition of lymphoproliferative disease according to the World Health Organization (WHO) classification. 35 Histopathologic examination consists of morphologic examination of cellular proliferation (cellular appearance and architectural pattern), usually combined with immunohistochemical analysis and molecular analysis.The exact modalities of biopsy depend on the anatomic site of the lesion and its relation to the eye: biopsy may be performed of the conjunctiva, an eyelid lesion, an orbital mass, or the lacrimal gland. However, sometimes patients have nodal involvement, an...