Defining Vitreoretinal Lymphoma
Genetic characteristics of PVRL
In recent years, PVRL data has indicated high rates of mutations in MYDD88 L265P and mutations near Y196 in the ITAM region of CD78, at 69~80% and 35%, respectively. MYD88 mutation, particularly L265P, has been detected in high frequencies in VRL, improving the diagnostic yield of vitrectomy specimens. Six patients with the CD79B Y196 mutation had shown relapse of CNS significantly earlier (16.5 months) than the eleven patients with the CD79B WT mutation (67 months : P = 0.0135).
Tests for MYD88 have been employed as one of the adjunctive diagnoses for VRL. In a group of 23 VRL patients and 40 uveitis patients, vitreous testing exhibited a sensitivity of 75% and a specificity of 100%. Recently, several groups of molecular profiling technologies have been employed to specify copy number losses of tumor suppressor genes, such as the CDKNA2. Next-Generation Sequencing (NGS) has also been used to screen whether there are mutations in multiple candidate genes. In addition to cellular material, DNA extracted from the aqueous humor or the cell-free supernatant of vitreous specimens can be used to detect mutations through NGS or digital droplet PCR.