Retinal tumors and cysts are rare, and they're usually benign, or non-cancerous. However, when a cancerous one occurs, it can be one of several types: retinoblastoma (ret-ih-no-blas-TOE-muh); retinal pigment epithelial (ep-ih-THEE-lee-ul), or RPE (R-P-E); RPE hypertrophy (high-PER-truh-fee); and von Hippel angioma (an-jee-OH-muh). Depending on its size and location on the retina, the growth can cause a partial or complete loss of vision or a detached retina. Treatment is determined by the cause, location, and character. Retinoblastoma is the most common retinal cancer of childhood and affects approximately 300 children in the U.S. each year. However, more than 90 percent of children can be cured of this cancer by early detection and removal of the affected eye. Some children sadly may have both eyes affected. This was the first cancer to be directly associated with a genetic abnormality, although it can occur without a family history. When cancers grow within the eye, they typically arise from part of the retina called the retinal pigment epithelium. RPE cancer is more common in females, more likely to cause inflammation, and less likely to respond to radiation, so ultrasound may be a helpful diagnostic tool. It's never been found to spread to other parts of the body, if it hasn't already spread prior to treatment. Angiomas are tumors composed chiefly of blood or lymph vessels. They can grow within the retina or optic nerve, either beneath or on top of the retina. They're usually not cancers and never spread to other organs. However, some people with this tumor may have cancerous tumors in other parts of the body, such as the kidneys or brain. In addition, if these tumors leak, secondary retinal detachments can cause blindness. Treatment is with laser or freezing techniques.