Retinoblastoma

Retinoblastoma first develops in the retina (the sensitive lining on the inside of the eye). If not treated, the cancer can metastasize (spread) outside the retina to the fluid inside the eye, the eye socket, the optic nerve, the brain and the bones and bone marrow. Most retinoblastomas are found and treated before they have spread outside the eyeball.

Ninety-five percent of children with retinoblastoma are diagnosed before they are 5 years old. Children with retinoblastoma in both eyes are usually diagnosed around the age of 12 months. Those with retinoblastoma in one are usually diagnosed when they are around 24 months old.

Forty percent of children with retinoblastoma have a genetic defect for retinoblastoma. This may be acquired or inherited. Throughout their lives, children with hereditary retinoblastoma are at higher risk to develop other cancers. They have a 45 percent chance of passing this genetic defect on to their children.

Sixty percent of children with retinoblastoma have nonhereditary retinoblastoma, which affects only one eye.

Symptoms of retinoblastoma include:

• Leukocoria (leukokoria), a white in the pupil (center) of the eye when light shines in the eye, such as when taking a flash photograph
• Strabismus, a condition in which the eyes appear to be looking in different directions
• Decreased vision
• Inflammation of the eye
• Eye pain

More than 95 percent of treated patients can be cured if the tumor is contained within the eye. For children with retinoblastoma in both eyes, about 70 to 80 percent of the eyes can be saved.

Diagnosis of Retinoblastoma

If your child has symptoms of retinoblastoma, pediatric ophthalmologists and pediatric oncologists at Riley at IU Health can perform diagnostic tests and exams, some of which may require diagnostic and interventional anesthesia. Diagnostic tests that are commonly used include:

• Eye exam. A pediatric ophthalmologist will thoroughly examine your child’s eyes while your child is under general anesthesia.
• Ultrasound. One of the most common diagnostic tests for retinoblastoma is ultrasound. It uses sound waves to create images of the inner eye. Ultrasound is usually performed under general anesthesia. It is used to make the diagnosis and evaluate the characteristics of the tumor such as calcification, location, size and spread within the eye.
• Magnetic resonance imaging (MRI). This imaging procedure uses a magnetic field and radio waves to produce highly detailed images of the eye and surrounding structures without using radiation. MRI is used to measure the tumor size and evaluate whether the retinoblastoma has spread outside of the eye and into the brain.

Tests that are rarely used to diagnose retinoblastoma include:

• Computed tomography (CT). In selected cases, radiologists use CT scans, which use X-rays, to create multiple cross-sectional images of the abdominal area to reveal tumors that have spread from the eyes.
• Positron emission tomography (PET) scan. Growing tumors absorb large amounts of sugar. PET scans use a small amount of radioactive glucose (a form of sugar) injected into the bloodstream to determine if retinoblastoma has spread anywhere else in the body.
• Bone scan. This test determines if the retinoblastoma has spread to the skull or other bones. Radiologists inject a small amount of radioactive material into a vein. Any cancerous areas in the bones will appear as bright spots in the images.
• Bone marrow biopsy. A small amount of bone marrow is biopsied and observed under a microscope to determine if the retinoblastoma has spread to the bone marrow.
• Lumbar puncture (spinal tap). This test can determine the presence of retinoblastoma cells in the cerebrospinal fluid, which surrounds the brain and spine, to determine if cancer has spread to the brain.