Diagnostic retinal biopsy in the management of secondary non-CNS vitreoretinal lymphoma masquerading as viral retinitis: a case report

Background: Intraocular lymphoma accounts for fewer than 1% of intraocular tumors. When the posterior segment is involved, it can be further classified as vitreoretinal or choroidal lymphoma. Vitreoretinal lymphoma (VRL) can rarely masquerade as an infectious retinitis making diagnosis and management challenging. Results: A 73-year-old woman with a history of non-central nervous system (CNS) involving diffuse large B-cell lymphoma (DLBCL) was referred for worsening blurry vision—visual acuity of count figures at 2 ft—in her right eye for 8 months. Dilated fundus examination of the right eye was significant for retinal whitening and dot-blot hemorrhages, which was concerning for a viral retinitis and guided initial management. Secondary intraocular lymphoma was also considered. The retinal disease continued to progress despite intravitreal and systemic antiviral therapy, and a diagnostic vitrectomy was inconclusive. A retinal biopsy was then performed, which showed DLBCL, confirming a diagnosis of secondary VRL. Three subsequent treatments with intravitreal methotrexate led to regression of the VRL. Conclusions: Our case highlights the utility of a retinal biopsy after an inconclusive diagnostic vitrectomy in a challenging scenario of VRL to establish a diagnosis and initiate successful treatment. A multidisciplinary team of providers was essential for diagnosis, comprehensive workup, medical and surgical management of the patient.