An overview of ocular adnexal lymphoid tumors.

In comparison with our earlier colleagues quoted in the introduction, we have made substantial progress in understanding the biology of ocular adnexal lymphoid tumors. While we have refined various categories with prognostic clinical value regarding possible associated systemic disease, none is foolproof and all have varying degrees of unpredictability. Comparatively well-differentiated histologic subtypes predominate among ocular adnexal lymphoid tumors. Polyclonal lesions occur less than half as often as monoclonal B-cell lesions. Molecular genetic studies have revealed small clones of monoclonal populations among the B-cells comprising most of the immunophenotypically polyclonal lesions, but no clonal genetic rearrangements have been uncovered within the preponderant constituent T-cell populations. The overall prognosis for ocular adnexal lymphoid tumors is excellent; when lumped together, 67% are not found to be associated with systemic disease with mean follow-ups of over 4 years. This is similar to experience with extranodal and extralymphatic lesions in other sites of the body, which also frequently have a small lymphocyte composition. The incidence of nonocular disease in all categories of our studies, however, will probably increase with the acquisition of longer follow-ups. Careful histopathologic evaluation is as good as immunophenotypic analysis of these lesions in predicting clinical outcome in terms of associated nonocular disease. Polyclonal and well-differentiated B-cell monoclonal lesions displayed equivalent clinical behavior. Benign polyclonal lesions may be associated with systemic disease but in a minority of cases (27%), as has also been determined in earlier studies. Clinical staging is the single most important predictor of associated monocular disease. In this study, patients with stage I-E disease had an 87% chance of not developing any nonocular lymphomatous lesion. We believe that this figure may also somewhat decrease with the passage of time. Precise anatomic localization of the lesion within the adnexa had considerable predictive value. Lesions of the conjunctiva fared the best; those of the orbit had an intermediate prognosis; while lid lesions had the worst prognosis. The most favorable prognosis would be held by a conjunctival lymphoid lesion in stage I-E composed of small lymphocytes. The fact that there is a fairly close equivalence in outcome between polyclonal and monoclonal well-differentiated lesions indicates that these lesions are in the vast majority of cases primary hyperplasias or primary lymphomas. The discovery by genetic probes of small monoclonal populations in immunophenotypically polyclonal lesions suggests that there is an evolution that goes on in situ.(ABSTRACT TRUNCATED AT 400 WORDS)