Choroidal lymphoma diagnosed by polymerase chain reaction–based clonality assessment

Abstract

Purpose: To report a case of primary choroidal lymphoma that was confirmed by polymerase chain reaction–based clonality testing. Case report: A 50-year-old woman presented with unilateral progressive vision loss. Fundus examination and B-ultrasonography demonstrated diffuse choroidal thickening without vitritis. Pars plana vitrectomy and subretinal biopsy were performed, and histopathologic analysis revealed choroidal B-cell lymphoid hyperplasia without evidence of neoplasia. Extraocular extension was ruled out, and transitory improvement was observed with oral steroids. After 1-year follow-up, she was referred to our hospital and clonality testing was performed using the samples taken months before. First, we used a forensic DNA extraction kit, and then, a multiplex polymerase chain reaction was carried out using the IgH Rearrangements Molecular Analysis Kit. Clonal rearrangement was identified for the immunoglobulin heavy chain framework regions 1 and 2, and B-cell choroidal lymphoma was confirmed. The patient began treatment with intravitreal rituximab, but no response was observed. Finally, complete regression was achieved using external beam radiotherapy. Conclusion: Polymerase chain reaction–based clonality testing can be a valuable tool to confirm a choroidal lymphoproliferative process.