Multimodal diagnostic imaging in primary vitreoretinal lymphoma

Background Primary vitreoretinal lymphoma (PVRL) is an aggressive lymphoma that may present with protean features and represents a diagnostic challenge. Given that patients with PVRL are at high risk of CNS involvement with a high mortality and morbidity rate, prompt diagnosis is crucial to initiate treatment early in the disease course. A multimodality imaging approach including fundus photography, fundus autofluorescence (FAF), optical coherence tomography (OCT), fluorescein and indocyanine angiography, and electroretinography (ERG) can provide information to establish a diagnosis and provide objective measures for management. We review key findings seen via these imaging modalities in patients with PVRL. Observations Fundus photography can highlight commonly seen patterns of PVRL including vitritis, subretinal disease, retinal pigment epithelial (RPE) abnormalities, optic nerve edema, retinal detachment, and less typical retinitis-like lesions. FAF can identify characteristic patterns of hyper- and hypoautofluorescent signal abnormalities in the macula. Spectral-domain OCT will demonstrate vitreous cells, RPE nodularity, and hyperreflectivity of the outer retina. The presence of a hyper-reflective band in the subretinal space and infiltrates between the RPE and Bruch's membrane can assist in distinguishing PVRL from choroidal lymphoma. Vertical hyperreflective columns (VHRLs) are another pertinent finding that may represent microinfiltrates of the tumor. OCT has proven to be a particularly useful modality in assessing the progress of treatment in PVRL. Fluorescein angiography can show RPE changes, which include granularity, late staining at the RPE level, and blockage. Indocyanine green angiography (ICGA) primarily shows hypocyanescence, which corresponds to PVRL lesions on fundus photography and may occur secondary to loss of RPE and choriocapillaris. Conclusion While PVRL remains a challenging disease to diagnose and follow, the use of a multimodality imaging approach may assist in establishing a diagnosis. Because of the anatomic spaces PVRL may affect, fundus photography, OCT, FAF, angiography, and ERG can identify key characteristics of the disease, differentiate PVRL from other diseases, and provide baseline information for targeted systemic and local therapies. Further assessment of anatomic and functional targets will aid our clinical application of multimodal imaging in the management of PVRL.