Recurrent pseudohypopyon in association with primary vitreoretinal lymphoma: a case report

Background: Primary vitreoretinal lymphoma (PVRL) is a rare and fatal ocular malignancy that is mostly classified as diffuse large B cell lymphoma (DLBCL). PVRL is often fatal because of its association with the central nervous system (CNS). PVRL frequently masquerades as uveitis and sometimes recurs in clinical findings as keratic precipitates (KPs) and subretinal lesions. Pseudohypopyon is one of the clinical findings of the local recurrence of PVRL and is treated with radiotherapy; however, the effectiveness of local control with an intravitreal injection of methotrexate (MTX) has not yet been determined. We herein present a case of recurrent vitreoretinal lymphoma that repeatedly developed pseudohypopyon and treated with intravitreal MTX. Case presentation: A 64-year-old woman was diagnosed with PVRL involving primary central nervous system lymphoma (PCNSL). She received radiotherapy to the whole brain and a local ocular treatment, which resulted in temporary remission of the disease. Pseudohypopyon was detected during the follow-up. It was 2-mm high, viscous, and swollen in the center. Anterior chamber biopsy revealed the presence of atypical lymphocytes, indicating the recurrence of DLBCL. Pseudohypopyon was treated with intravitreal methotrexate and completely disappeared. Pseudohypopyon has since repeatedly appeared and been treated with intravitreal MTX each time. The recurrence of PVRL with KPs and subretinal invasion was treated with intravitreal MTX each time. Recurrence with pseudohypopyon was not simultaneous with KPs or subretinal invasion. No CNS involvement was detected during the observation period. Conclusions: Pseudohypopyon is one of the signs of recurrent vitreoretinal lymphoma. Although pseudohypopyon was temporarily controlled with intravitreal MTX, this treatment did not completely induce its remission.