Table 1:

The International Classification of Retinoblastoma4

GroupFeatures
ATumor ≤3 mm
BTumor >3 mm or macular location (≤3 mm to foveola), juxtapapillary location (≤1.5 mm to disc), clear subretinal fluid (≤3 mm from margin)
CTumor with subretinal and/or vitreous seeds ≤3 mm from tumor
DTumor with subretinal and/or vitreous seeds >3 mm from tumor
EExtensive retinoblastoma occupying >50% of globe or neovascular glaucoma; opaque media from hemorrhage in anterior chamber, vitreous, or subretinal space; invasion of postlaminar optic nerve, choroid (>2 mm), sclera, orbit, anterior chamber