Uveitis Masquerade: Intraocular Lymphoma
Primary vitreoretinal lymphoma was previously referred to as reticulum cell sarcoma, histiocytic lymphoma, and non-Hodgkin lymphoma of the central nervous system. Most cases are aggressive large B-cell tumors. Half of all cases of primary vitreoretinal lymphoma occur in patients older than 60 years. Most patients with primary vitreoretinal lymphoma will develop central nervous system (CNS) involvement. Conversely, of patients who present with CNS involvement, approximately 20% will have intraocular involvement. HIV infection is associated with an increased risk of lymphoma that ranges from 50-fold (with potent antiretroviral therapy) to more than 500-fold (prior to—or without access to—potent antiretroviral therapy). Clinical features that are suggestive of lymphoma include an incomplete or transient response to corticosteroid treatment, the presence of atypical vitreous cells, which may be uncharacteristically white and/or align in sheets, and the presence of subretinal infiltrates, which may be transient and/or shift location over time (Fig 11-12). Optic nerve head edema and serous retinal detachment can also occur. Patients with suspected primary vitreoretinal lymphoma should undergo magnetic resonance imaging (MRI) of the brain with contrast as well as a spinal tap for cytologic studies to evaluate for CNS involvement. A confirmatory CNS or vitreoretinal biopsy is usually performed. It is notoriously difficult to arrive at a diagnosis based on tests of a vitreous specimen because of the low cell concentrations and the propensity of lymphoma cells to undergo autolysis. Because corticosteroids will also reduce cell count, it is best to stop any corticosteroid treatments for a period of weeks before a planned biopsy. Best results are achieved with rapid test processing and analysis by cytology, immunoglobulin or T-cell receptor gene rearrangement studies, flow cytometry, and cytokine analyses. Current management practices involve both chemotherapy and radiation treatment. Intravitreal injection of methotrexate and rituximab can be effective at controlling intraocular disease, but the recurrence rate is high and long-term prognosis guarded.
In contrast, uveal lymphoma is usually more indolent and is associated with systemic lymphoma in up to one-third of cases. Characteristic clinical findings include uveal thickening, which often produces a birdshot uveitis–like fundus appearance, with or without serous retinal detachment (Fig 11-13). Episcleral involvement may manifest anteriorly as salmon-colored conjunctival infiltration or posteriorly as a juxtascleral mass on ultrasound. Biopsy of affected tissues can confirm the diagnosis. Evaluation for systemic involvement includes use of computed tomography (CT) or combined CT and positron emission tomography (PET) imaging of the thorax, abdomen, and pelvis.
Figure 11-12 Intraocular lymphoma. A, Color fundus photograph shows sub–retinal pigment epithelial infiltrates. B, Cytologic preparation of vitreous cells reveals many atypical cells with large nuclei and multiple nucleoli. Cell ghosts (arrows) are also present.
(Courtesy of David J. Wilson, MD.)
Figure 11-13 Uveal lymphoma. A, Fundus photograph demonstrates birdshot uveitis–like fundus appearance. B, B-scan ultrasound reveals characteristic uveal thickening (arrows).
(Courtesy of Stephen J. Kim, MD.)
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.