Overview

Cancer begins when normal cells begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body).

Retinoblastoma is a rare cancer that begins in the part of the eye called the retina. The retina is a thin layer of nerve tissue that coats the back of the eye and enables the eye to see. Most often, retinoblastoma is unilateral, meaning only in one eye, but can sometimes be in both eyes, called bilateral. If retinoblastoma spreads, it can spread to the lymph nodes, bones, or the bone marrow (the soft, spongy-like material found inside large bones). Rarely, it involves the central nervous system (CNS; brain and spinal cord).

Children may be born with retinoblastoma, but the disease is rarely diagnosed at birth. Most children who begin treatment before the retinoblastoma has spread beyond the eye are cured. An important goal of treatment in children with retinoblastoma is preserving vision.

Find out more about basic cancer terms used in this section.