Utility of liquid-based cytology and cell block obtained by vitrectomy under infusion to diagnose vitreoretinal lymphoma

PURPOSE: To confirm the definitive diagnostic method of vitreoretinal lymphoma by vitrectomy under infusion. STUDY DESIGN: Retrospective, pathological analysis METHODS: Twenty-two patients participated in this study; 29 vitreous samples were obtained under infusion. Liquid-based cytology (LBC) was performed by targeting areas with a high cell concentration while observing the surgical field under infusion. Cell block analysis was performed by the vitreous cell components in the intraocular irrigating fluid. RESULTS: Our vitreous sample collection did not result in adverse events. In LBC samples, atypical large lymphoid cells were identified in 89.7%. These samples contained between 30 and over 10,000 atypical large lymphoid cells. Necrosis was observed in 76.9% in the background of LBC samples. In cell block samples, atypical large lymphoid cells were identified in 87.0%. Immunohistochemical staining revealed the following immunophenotypes for the lymphoid cells: CD20 (100%), CD79a (100%), CD10 (0%), BCL6 (57.1%), MUM1 (85.7%), and Ki-67 LI 66.3±12.7%. CONCLUSION: This method ensures safety and high diagnostic accuracy, thereby contributing to the definitive diagnosis of vitreoretinal lymphoma.