Acute Retinal Necrosis or Lymphoma?

PURPOSE: To describe an atypical presentation of primary vitreoretinal lymphoma (PVRL) mimicking acute retinal necrosis (ARN) and to identify its initial findings that argue against necrotizing viral retinitis. METHODS: Observational case report with clinical and imaging assessment, aqueous humor polymerase chain reaction (PCR), and diagnostic pars plana vitrectomy with cytologic, immunophenotypic and molecular analysis. RESULTS: , was negative. No antiviral therapy was administered. Diagnostic vitrectomy revealed atypical CD20-positive lymphoid cells with MYD88 L265P mutation and an elevated interleukin-10/interleukin-6 ratio, confirming PVRL. CONCLUSION: PVRL may closely mimic ARN, particularly in unilateral cases with granulomatous features. In this eye, three findings argued against necrotizing viral retinitis: massive keratic precipitates without ocular congestion, retinal lesions lacking the peripheral circumferential pattern of ARN, and sub-retinal pigment epithelial infiltration on OCT. All were available at the first visit despite severe media opacity, and should shorten the interval to vitreous biopsy.