Intraocular lymphoma: Diagnostic approach and immunophenotypic findings in vitrectomy specimens

Context. - Diagnosis and classification of primary intraocular lymphoma can be challenging because of the sparse cellularity of the vitreous specimens. Objective. - To classify and clinically correlate intraocular lymphoma according to the World Health Organization (WHO) classification by using vitrectomy specimens. Design. - Clinical history, cytologic preparations, flow cytometry reports, and outcome of 16 patients diagnosed with intraocular lymphoma were reviewed. Results. - The study group included 10 women and 6 men. The mean age of the patients was 63 years (range, 19-79 years). Eleven patients had central nervous system involvement and 6 patients had systemic involvement. All cases were adequately diagnosed and classified according to the WHO classification by using combination of cytologic preparations and 4-color flow cytometry with a limited panel of antibodies to CD19, CD20, CD5, CD10, and κ and λ light chains. The cases included 9 primary diffuse large B-cell lymphomas of the CNS type; 2 diffuse large B-cell lymphomas, not otherwise specified; 1 extranodal, low-grade, marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT); 1 precursor B-lymphoblastic lymphoma; and 3 peripheral T-cell lymphomas, not otherwise specified. Of note, all 11 cases of diffuse large B-cell lymphoma were CD10^-. All the patients received systemic chemotherapy and radiation therapy. Only 4 patients were free of disease at last follow-up (range, 18 months to 8 years), with severe visual loss. Conclusions. - Intraocular lymphoma cases can be adequately classified according to the WHO classification. Diffuse large B-cell lymphoma, CD10^- and most likely of non-germinal center B-cell-like subgroup, is the most common subtype of non-Hodgkin lymphoma in this site, in contrast to ocular adnexal lymphoma for which MALT lymphoma is the most common subtype.