Histological features of ocular adnexal lymphoma (REAL classification) and their association with patient morbidity and survival.

BACKGROUND The histological characteristics of ocular adnexal lymphomas have previously provided only a limited guide to clinical outcome for affected patients. This clinicopathological relation was re-examined using the Revised European American Lymphoma (REAL) system to classify the tumours in a large cohort of patients. METHODS The biopsies and clinical follow up data for 192 patients with ocular adnexal lymphoma were reviewed, the biopsies being regraded in accordance with the REAL classification. For each of five histological groups, logistic regression analysis was used to determine the odds ratios (OR) for the presence of systemic disease at the time of orbital diagnosis and Cox regression analysis was used to assess the hazard ratios (HR) for disseminated disease and lymphoma related death. For 108 patients in whom extraorbital spread occurred, the histological category of lymphoma was compared with the sites of dissemination. RESULTS At presentation, the frequency of previous or concurrent extraorbital disease increased from marginal zone lymphoma (OR 1.0), diffuse lymphoplasmacytic/lymphoplasmacytoid lymphoma (OR 2.3), follicle centre lymphoma (OR 3.8), diffuse large B cell lymphoma (OR 4.0) to other histological lymphoma variants (OR 26.8). For all histological types, the estimated risk of extraorbital disease and lymphoma related death continued for many years and the proportion of patients with at least one extraorbital recurrence after 5 years was 47% for MZL, 48% for LPL, 64% for FCL, 81% for DLCL, and 95% for other lymphoma variants. The corresponding estimated rates for 5 year lymphoma related mortality were 12%, 19%, 22%, 48%, and 53% respectively. CONCLUSIONS Patients with ocular adnexal lymphoma can be classified by REAL into five distinct groups, which show a progressive increase in the risks of extraorbital disease at diagnosis, of disease dissemination with time, and of tumour related death.