Treatment of benign orbital pseudolymphomas with the monoclonal anti-CD20 antibody rituximab.

Objective: To report the results of treating patients with orbital pseudolymphomas with the anti-CD20 monoclonal antibody rituximab.

Patients And Methods: Patients were included in the study if they had an orbital mass and biopsy-proven orbital pseudolymphomas between January 1, 1998, and December 31, 2005. The study focused on patients treated with rituximab.

Results: Ninety-eight patients were evaluated, and the biopsy results revealed malignant non-Hodgkin lymphoma in 72 (73%); the other 26 (27%) had a pseudolymphoma. Eleven (42%) of the 26 patients with a pseudolymphoma were treated with rituximab, 375 mg/m2, intravenously each week for 4 doses, and 10 (91%) of the 11 responded. Seven patients were either treated with maintenance rituximab or successfully retreated with rituximab after relapse. None of the 10 responders has become refractory to rituximab.

Conclusion: Benign lymphoproliferative tumors are responsive to monoclonal antibody therapy targeted to B lymphocytes. Rituximab should be considered a treatment option for orbital pseudolymphomas.