General Information About Retinoblastoma
Key Points for this Section
Retinoblastoma is a disease in which malignant (cancer) cells form in
the tissues of the retina.
The retina is the nerve tissue that lines the inside of the back of the eye. The retina senses light and sends images to the brain by way of the optic nerve.Anatomy of the eye, showing the outside and inside of the eye including the sclera, cornea, iris, ciliary body, choroid, retina, vitreous humor, and optic nerve. The vitreous humor is a gel that fills the center of the eye.
Anatomy of the eye, showing the outside and inside of the eye including the sclera, cornea, iris, ciliary body, choroid, retina, vitreous humor, and optic nerve. The vitreous humor is a gel that fills the center of the eye.
Although retinoblastoma may occur at any age, it usually occurs in children younger than 5 years, most often younger than 2 years. The tumor may be in one eye or in both eyes. Retinoblastoma rarely spreads from the eye to nearby tissue or other parts of the body.
Retinoblastoma is sometimes caused by a gene mutation passed from the parent to the child.
Retinoblastoma is sometimes inherited (passed from the parent to the child). Retinoblastoma that is caused by an inherited gene mutation is called hereditary retinoblastoma. It usually occurs at a younger age than retinoblastoma that is not inherited. Retinoblastoma that occurs in only one eye is usually not inherited. Retinoblastoma that occurs in both eyes is thought to be inherited.
When hereditary retinoblastoma first occurs in only one eye, there is a chance it will develop later in the other eye. After diagnosis of retinoblastoma in one eye, regular follow-up exams of the healthy eye should be done every 2 to 4 months for at least 28 months. After treatment for retinoblastoma is finished, it is important that follow-up exams continue until the child is 5 years old.
Treatment for both types of retinoblastoma should include genetic counseling (a discussion with a trained professional about inherited diseases). The parents of a child with retinoblastoma should have an eye exam by an ophthalmologist (a doctor with special training in diseases of the eye) and genetic counseling about whether they should be tested for the gene that causes retinoblastoma and the risk of the child's brothers or sisters developing retinoblastoma. The child's brothers and sisters also should have regular eye exams by an ophthalmologist until age 5 years.
A child who has hereditary retinoblastoma is at risk for developing trilateral retinoblastoma and other cancers.
A child who has hereditary retinoblastoma is at risk for developing pineal tumors in the brain. This is called trilateral retinoblastoma and usually occurs more than 20 months after retinoblastoma is diagnosed. Regular screening using MRI (magnetic resonance imaging) every 6 months for 5 years may be recommended for a child with hereditary retinoblastoma or with retinoblastoma in one eye and a family history of the disease. CT scans (computerized tomography) should not be used for routine screening to avoid exposing the child to ionizing radiation. Hereditary retinoblastoma also increases the child's risk of developing other types of cancer such as bone or soft tissue sarcoma or melanoma in later years. Regular follow-up exams are important.
Possible signs of retinoblastoma include "white pupil" and eye pain or redness.
These and other symptoms may be caused by retinoblastoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems
- Pupil of the eye appears white instead of red when light shines into it. This may be seen in flash photographs of the child.
- Eyes appear to be looking in different directions.
- Pain or redness in the eye.
Tests that examine the retina are used to detect (find)
and diagnose retinoblastoma.
The following tests and procedures may be used:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken. The doctor will ask if there is a family history of retinoblastoma.
- Eye exam with dilated pupil: An exam of the eye in which the pupil is dilated (opened wider) with medicated eyedrops to allow the doctor to look through the lens and pupil to the retina. The inside of the eye, including the retina and the optic nerve, is examined with a light. Depending on the age of the child, this exam may be done under anesthesia.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the eye, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the eye. This procedure is also called nuclear magnetic resonance imaging (NMRI).
Retinoblastoma is usually diagnosed without a biopsy (removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer).
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
- The stage of the cancer.
- The age of the patient.
- How likely it is that vision can be saved in one or both eyes.
- The size and number of tumors.
- Whether the patient has glaucoma.
- Whether trilateral retinoblastoma occurs.