Study On Classification Of The Ocular Adnexal Lymphoma, Differential Diagnosis Between MALT-type Lymphoma And Reactive Lymphoid Hyperplasia Of The Ocular Adnexa And Predictive Value Of The Ki-67 And P53

Object: Ocular adnexal lymphoma is a kind of commonly seen malignant orbital tumor. In the past, the error rate of histopathologic diagnosis and ability to predict clinical outcome were highly due to the lack of the acceptable standard histopathologic classification and immunologic and molecular biologic techniques, which happened in the treatments and predictions. So, classification and differential diagnosis are very important. In this study, using immunologic and molecular biologic techniques, 34 cases of ocular adnexal lymphomas were classified according to the new WHO classification. 33 cases are non-Hodgkin lymphoma and one is a granular sarcoma. 29 cases of MALT-type lymphomas, which mostly happened, were studied in thedifferential diagnosis and the prediction of prognosis. Results:1. 33 cases ocular adnexal lymphoma, including the four subtypes, were classified as follows: there are 29 cases of extranodal marginal-zone B-cell lymphoma(87.9%), 2 cases of diffuse large B-cell lymphoma(6.1 %) and 1 case of plasmacytoma (3.0%), as well as 1 case of T-cell lymphoma( 3.0%). The result shew that the ocular adnexal lymphoma are mostly marginal zone B cell lymphoma, mucosa associated lymphoid tissue type(MZL-MALT).2. 29 cases of MALT-type lymphoma expressed B-cell markers and not expressed T-cell markers, where as 8 cases of reactive lymphoid hyperplasia all expressed B and T cell markers, and T-cell represented more than 30%. 11 cases shew immunoglobin light chain restriction (K or A, positive) and 15 cases shew a monoclonal band by PCR in the MALT-type lymphoma. 8 cases of hyperplasia shew K or X both positive and a polyclonal picture in PCR. No significant differences in the clinical characteristics were observed between the MALT-type lymphoma and reactive lymphoid hyperplasia in ocula adnexa. Immunohistochemistry and molecular biology is very important in the differencitated diagnosis between the MZL-MALT with reactive hyperplasia.3. The positive ratio of Ki-67 and P53 protein were 58.6%, 55.2% respectively in ocular adnexal lymphoma and 73.3%, 60% respectively in gastrointestinal tract lymphomas. The ratio of Ki-67 and P53 protein overexpressed in gastrointestinal tract is higher than that in ocular adnexa. There was no high-grade transformation in ocular adnexal lymphoma, but high-grade transformation was observered in 5 of 15 cases of the gastrointestinal tract lymphomas. The result shew that MZL-MALT of theocular adnexal lymphoma differ from the gastrointestinal MZL-MALT and rarely transformed to high- grade.ConclusionThe new WHO classification is suitable for the subdivision of ocular adnexal lymphomas. The MALT-type lymphoma is most common type in the ocular adnexa. Immuhistochemistry analysis and PCR are helpful to identify the MALT-lymphoma and the reactive lymphoid hyperplasia. The ratio of high-grade transformation of MALT-type lymphoma in ocular adnexa is less than that in gastrointestinal tract. The expression of Ki-67 and P53 in ocular adnexal lymphoma is lower than that in gastrointestinal tract's.