<prompt> Retinoblastoma spreads to CNS through:DirectLymphaticArterialVitreous  <response>: a. DirectRef: Nelsons 20e p 2476-2478, Ghai 8e 614-615Spread of Retinoblastoma:By direct extension to choroid; Along the optic nerve beyond lamina cribrosa to the CNS, orBy hematogenous or lymphatic spread to distant sites, including bones, bone marrow, and lungs. 