Retinoblastoma

The first step in treating your child is forming an accurate and complete diagnosis. In addition to a complete medical history and physical examination, your child’s doctor may order one or more tests to determine the cause of her symptoms. Most often, the tests are performed under general anesthesia, so your child won’t feel a thing. Tests include:

• complete eye examination—While your child is under anesthesia, the doctor will dilate her pupils and examine the inside of her eye, including the retina and optic nerve.

• computerized tomography scan (CT scan)—This is an imaging procedure that shows detailed pictures of areas inside the body, including the eye. Your child may be given a dye to help the picture of her eye show up more clearly.

• magnetic resonance imaging (MRI)—This is an imaging procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.

• ultrasound of the eye—Ultrasonography is an imaging procedure that uses sound waves to produce an image of body tissues, and can let doctors get a close look at your child’s eye.

Retinoblastoma is usually diagnosed without a biopsy.

In addition, our genetic counselors will meet with you and discuss the possibility of taking a blood sample and running tests to look for the abnormal retinoblastoma gene. This allows us to confirm a diagnosis of retinoblastoma, and determine whether the mutation is heritable.

Stages of retinoblastoma

During the diagnosis procedure, your child’s doctors will be looking to determine the size, number and location of the tumors; and whether they have spread to the other parts of the body. This is called staging and it’s an important step in planning treatment. 

Various staging systems can be used for retinoblastoma. Until recently, the Renee-Ellsworth classification system was the most popular method, but this is now being replaced by the International Classification of Retinoblastoma (ABC classification).

International (ABC) Classification System

Group A

• small tumor(s) located only in the retina
• no tumor is larger than 3 millimeters (mm)
• no tumor is closer than 2 disc diameters (DD) from the fovea (the central “pit” of the retina) or 1 DD from the optic nerve
• no vitreous seeding (tumor floating in the eye) or retinal detachment

Group B

• tumor(s) located only in the retina
• any location in the retina
• no vitreous seeding
• no retinal detachment more than 5 mm from tumor base

Group C

• fine, diffuse (spread throughout) or localized (located in one spot) vitreous seeding
• retinal detachment: more than Group B and up to total retinal detachment
• no vitreous/subretinal “snowballs” or masses

Group D

• massive vitreous/subretinal seeding
• vitreous or subretinal snowballs/masses
• retinal detachment: more than Group B and up to total retinal detachment

Group E

No visual potential, or presence of one or more:

• tumor in CB/anterior segment
• neovascular glaucoma
• vitreous hemorrhage (bleeding from the eye)
• phthisical/prephthisical (deteriorating) eye
• hyphema (blood in the anterior of the eye)/corneal staining
• orbital cellulitis-like presentation
• tumor anterior to anterior hyaloids

Recurrent

• cancer comes back after treatment

Retinoblastoma may also be classified as intraocular (inside the eye) or extraocular (the cancer has spread outside the eye).

After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and outline the best treatment options.