The characteristics of tumor cells of primary vitreoretinal lymphoma (PVRL) have not been defined, although researches have shown that most cases are of diffuse large B-cell lymphoma (DLBCL). To determine the subtype and biological characteristics of tumor cells of PVRL, we performed a gene expression profiling analysis. RNA was extracted from the vitreous fluid of 7 PVRL patients and from nodal samples of 10 DLBCL patients: 6 of germinal center B-cell (GCB) type and 4 of activated B-cell (ABC) type determined by Hans' criteria. Six PVRL samples showed gene expression profiles that were similar to each other. The patterns were different from those of the ABC-type nodular DLBCL but relatively close to those of the GCB-type nodular DLBCL. Interestingly, all of the 6 examined PVRL samples had either MYD88L265P or mutation in the immunoreceptor tyrosine-based activation motif (ITAM) region of CD79B. Five PVRL patients with similar gene expression profiles were treated with a standardized regimen: intravitreal administration of methotrexate (MTX) followed by six courses of systemic high doses of MTX. As a result, 2 patients had CD79B mutations and showed early central nervous system (CNS) progression. Patients without CNS progression did not have this mutation. In conclusion, PVRL had unique genetic features: an expression pattern different from ABC-type and relatively close to GCB-type DLBCL. CD79B mutations showed potential to serve as prognostic markers for CNS progression.
Keywords: CD79B; GCB-type DLBCL; diffuse large B-cell lymphoma; gene expression profiling; primary vitreoretinal lymphoma.
© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.