Deep sequencing as a diagnostic tool in patients with suspected primary vitreoretinal lymphoma

To compare the diagnostic utility of metagenomic deep sequencing (MDS) to cytology, flow cytometry and gene rearrangement by PCR in ocular samples of patients with suspected vitreoretinal lymphoma (VRL).

Patients with suspected VRL underwent ocular sampling of one or both eyes at the Emory Eye Center from September 2017 to June 2022. Ocular samples were evaluated with MDS and conventional diagnostics. MDS was performed at the Ralph and Sophie Heintz Laboratory at the F.I. Proctor Foundation. Relevant demographic and clinical data were retrospectively collected from medical records. Patients were diagnosed with VRL based on clinical assessment and conventional diagnostic testing.

This study included 13 patients with suspected VRL who underwent diagnostic vitrectomy, including 1 patient who had an additional subretinal biopsy. Six patients (46.2%) were diagnosed with VRL. Among patients diagnosed with VRL, MDS detected pathogenic mutations in 5 out of 6 patients (83.3%) while cytology was positive for VRL in 4 out of 6 patients (66.7%), flow cytometry in 4 out of 4 patients (100.0%) and PCR in 4 out of 4 patients (100.0%). MDS detected mutations in MYD88 in 2 out of 6 patients diagnosed with VRL. In 7 patients (53.8%) not diagnosed with VRL, MDS detected pathogenic lymphoma mutations in 2 patients (28.6%).

MDS detected pathogenic mutations in five out of six patients diagnosed with VRL, including in two patients with negative cytology, demonstrating its potential to improve diagnostic rates of VRL as an adjunctive test.