Retinoblastoma spreads to CNS through:
a. Direct(Ref: Nelson's 20/e p 2476-2478, Ghai 8/e 614-615)Spread 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.
Direct
Lymphatic
Arterial
Vitreous
Childhood Tumors