Ocular Adnexal Lymphoma

Abstract

Ocular adnexal lymphomas arise from the orbital structure, including the conjunctiva, eyelid, lacrimal gland, and retrobulbar region. The majority of ocular adnexal lymphomas are extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma), which usually tend to remain localized for a long time and have an indolent natural history. Among various treatment options for localized ocular adnexal MALT lymphoma, such as chemotherapy, rituximab, antibiotic therapy, surgery, and watchful waiting, radiation therapy alone is the most promising modality as the definitive treatment. Moderate doses (24–30 Gy) of radiation therapy are safe and can achieve local control in greater than 95% of the patients. To avoid severe and incurable adverse events on the eyes, doses higher than 30 Gy should not be delivered for MALT lymphoma. Localized diffuse large B-cell lymphomas (DLBCL), which comprise a minority of primary ocular adnexal lymphomas, are commonly treated with a combined modality therapy consisting of chemotherapy with rituximab followed by radiation therapy. For DLBCL, a dose of 30 Gy is recommended for patients who had a complete response to immunochemotherapy. In the case of electron beam therapy for conjunctival lymphoma, lens shielding can effectively reduce the risk of cataract formation.