VITREORETINAL INVOLVEMENT BY INDOLENT T-CELL LYMPHOPROLIFERATIVE DISORDER OF THE GASTROINTESTINAL TRACT DIAGNOSED BY FLUORESCENCE IN SITU HYBRIDIZATION

The purpose of this study was to describe an exceedingly rare presentation of secondary vitreoretinal involvement by the uncommon entity "indolent T-cell lymphoproliferative disorder of the gastrointestinal tract" and illustrate the utility of fluorescence in situ hybridization for diagnosis.Methods:This is a case report.Results:A 57-year-old woman with presumed iritis on chronic topical prednisolone acetate presented with increased vitreous opacities in the right eye. She had a history of biopsy-confirmed indolent T-cell lymphoproliferative disorder of the gastrointestinal tract involving the stomach and duodenum, JAK2-rearrangement positive, controlled on maintenance oral methotrexate. Vitreous biopsy was unremarkable with small CD3-positive and CD4-positive and CD20-negative lymphocytes, along with histiocytes and fibroblasts. Immunostains showed CD4 positivity, and fluorescence in situ hybridization revealed a JAK2 gene rearrangement, consistent with the patient's previously diagnosed indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. Intravitreal methotrexate injections were started in the right eye. MRI of the brain and lumbar puncture with cytology, MYD88, IL10, and flow cytometry performed at the time of right eye vitreoretinal lymphoma diagnosis revealed no evidence of central nervous system lymphoma, but subsequent bone marrow biopsy demonstrated 5% involvement by indolent T-cell lymphoproliferative disorder of the gastrointestinal tract, JAK2-rearrangement positive, with a lung nodule on PET computed tomography. She returned 4 months later with fatigue, night sweats, and blurry vision in the left eye with vitreous and anterior chamber cellular infiltration and retinal vasculitis.Conclusion:T-cell vitreoretinal lymphoma is rare, and diagnosis can be challenging. Despite inconclusive cytology in this case, interphase fluorescence in situ hybridization detected a JAK2 gene rearrangement, which confirmed the involvement by indolent T-cell lymphoproliferative disorder of the gastrointestinal tract and prompted appropriate treatment and workup for recurrent systemic or central nervous system lymphoma.