Ocular Adnexal Lymphoma: Clinical Behavior of Distinct World Health Organization Classification Subtypes
Purpose: To evaluate the clinical behavior and treatment outcome of ocular adnexal lymphomas classified by the World Health Organization Classification, with emphasis on marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT).
Methods: The clinico-pathologic materials were reviewed in 98 consecutive patients treated for ocular adnexal lymphoma. Fourteen patients had prior lymphoma while 84 patients had primary disease (75% stage I, 6% stage III, 19% stage IV.) Radiation (photons/electrons) was administered to 102 eyes to 30.6 Gy median dose. Mean follow-up was 82 months.
Results: The most common subtypes among primary patients were MALT (57%) and follicular (18%) lymphoma. The 5-year actuarial local control rate in 102 irradiated eyes was 98%. Among the low-grade lymphomas, 5-year local control was correlated with radiation dose in the MALT lymphoma subgroup (N = 53): 81% for <30 Gy and 100% for 
30Gy (p<0.01). For the non-MALT low-grade lymphomas such as follicular lymphoma (N = 30), local control was 100% regardless of dose. For 39 stage I MALT lymphoma patients treated with radiation alone, the distant-relapse-free survival was 75% at 5 years and 45% at 10 years. Distant relapses were generally isolated and successfully salvaged by local therapy. The overall survival for this subgroup was 81% at 10 years, with no deaths from lymphoma.
Conclusions: Dose-response data suggest the optimal radiation dose for MALT lymphoma of the ocular adnexa is 30.6-32.4 Gy in 1.8 Gy fractions while follicular lymphoma is adequately controlled with doses in the mid 20 Gy range. The substantial risk of distant relapse in stage I ocular adnexal MALT lymphoma underscores the importance of long-term follow-up for this disease and the need for additional comparative studies of MALT lymphoma of different anatomical sites. (2003;57:1382-1391)
