Primary vitreoretinal high-grade B-cell lymphoma: A Case report and a brief review of the literature

Primary vitreoretinal lymphoma (PVRL) is a rare, aggressive form of non-Hodgkin lymphoma that primarily affects the retina and vitreous humor. Classified as a subset of primary central nervous system lymphoma (PCNSL), it usually manifests as a diffuse large B-cell lymphoma (DLBCL) and is notorious for mimicking chronic uveitis.
A 68-year-old immunocompetent female presented with a four-month history of blurred vision and mild photophobia, with fundoscopy showing vitreous haze, multifocal creamy-yellow subretinal infiltrates, and retinal pigment epithelium changes. She was originally treated for inflammatory uveitis with doxycycline and corticosteroids. The diagnosis of PVRL was confirmed by polymerase chain reaction (PCR) demonstrating IgH gene rearrangement and monoclonality, along with detection of the MYD88 L265P mutation. Treatment was methotrexate twice weekly for four weeks, followed by methotrexate weekly for eight weeks and monthly maintenance. 
After 3 months, the haze had cleared, and the subretinal infiltration had resolved, with improvement in visual acuity. Eleven months later, a brain MRI showed a 2-cm enhancement lesion in the frontal lobe and multifocal periventricular nodules. She received high-dose methotrexate with rituximab followed by whole-brain radiotherapy. Six months later, the repeat MRI showed an increase in size of the left frontal lobe and several new subependymal and leptomeningeal enhancements. The patient was transitioned to palliative care with the goal of care to be comfort measures. The patient died 9 months later. 
This case highlights the diagnostic challenges of primary vitreoretinal lymphoma and aims to increase awareness of this rare disease.