Retinoblastoma occurs when retinal nerve cells genetically mutate, causing them to grow and multiply, eventually forming a tumor. These cells usually spread into the eye and nearby structures, and can also spread to other areas of the body (metastasize), including the brain and spine.
It is usually not known what causes the genetic mutations that lead to retinoblastoma; however, children may inherit a genetic mutation from their parents. Children with hereditary retinoblastoma tend to develop it at an earlier age, and it usually occurs in both eyes.
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