# How is retinoblastoma diagnosed in children?

Canonical page: https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children
Language: en
Category: oncology
Publisher: ClinicsJo
Published: 2026-09-13T17:52:53.766Z
Content updated: 2026-09-13T17:52:53.766Z
Translation (ar): https://clinicsjo.com/ar/faq/how-is-retinoblastoma-diagnosed-in-children

Retinoblastoma in children is primarily diagnosed through a combination of specialized examinations focusing on the eye and retina. The diagnostic process typically begins with a comprehensive eye exam, followed by imaging studies such as ultrasounds and magnetic resonance imaging (MRI), and may also include genetic testing to determine the type of cancer. A biopsy (taking a tissue sample from the tumor) is rarely necessary to diagnose retinoblastoma. Early diagnosis can reduce the intensity of the required treatment [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>).

## Initial Eye Examination

When retinoblastoma is suspected, a doctor performs a comprehensive eye exam. This exam usually involves dilating the pupil with special drops, which allows the doctor to see the retina and optic nerve clearly [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). In very young children, this exam may be performed under anesthesia to ensure accuracy and the child's comfort [\[4\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S4>). Common signs that parents may notice and that prompt a doctor's visit include the pupil appearing white instead of red when light is shone into it, especially in flash photography, or noticing that the eyes appear to look in different directions (strabismus) [\[5\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S5>).

## Imaging Tests

Imaging tests are a crucial part of diagnosing retinoblastoma and determining the extent of its spread. These tests include:

- **Ocular Ultrasound:** This procedure uses high-energy sound waves to create images of the internal tissues of the eye. A small probe is gently placed on the eye's surface after numbing it with drops, and the resulting images show details inside the eye [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>), [\[4\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S4>).

- **Magnetic Resonance Imaging (MRI):** MRI uses a magnetic field, radio waves, and a computer to create detailed images of the eye and surrounding areas, such as the brain. MRI is preferred over computed tomography (CT) in routine screening to avoid exposing the child to ionizing radiation [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>).

- **Fluorescein Angiography:** A fluorescent dye is injected into a vein in the arm, then a special camera takes pictures of the blood vessels in the eye to evaluate blood flow and identify any blocked or leaking areas [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>).

## Genetic Testing and Family History

Family history plays an important role in the diagnosis of retinoblastoma. If there is a family history of the disease, the child should undergo regular eye exams early on [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). Genetic testing can determine whether a child has the hereditary or non-hereditary type of retinoblastoma. The hereditary form is believed to occur when there is a mutation in the RB1 gene, which can be inherited from parents or occur shortly after conception [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). Knowing if the cancer is hereditary can influence follow-up plans and increase the risk of developing other types of cancer in the future, such as pineal gland tumors in the brain [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). You can learn more about this disease by visiting the page [Childhood Eye Cancer: Retinoblastoma, Early Diagnosis, and Treatment (Arabic)](<https://clinicsjo.com/ar/articles/childhood-eye-cancer-retinoblastoma-early-diagnosis-treatment>).

## What Happens After Diagnosis?

After diagnosing retinoblastoma, additional tests are conducted to determine if cancer cells have spread within the eye or to other parts of the body, a process known as staging [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). Staging includes tests such as an MRI of the brain, bone marrow aspiration, and a lumbar puncture (to collect cerebrospinal fluid) if the doctor suspects the cancer has spread outside the eye [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>). Treatment options and chances of recovery depend on several factors, including the size and location of the tumor, whether the cancer is in one or both eyes, the child's age, and whether it has spread to other parts of the body [\[2\]](<https://clinicsjo.com/en/faq/how-is-retinoblastoma-diagnosed-in-children#source-S2>).

## Medical references

- [Retinoblastoma Treatment (PDQ®)–Patient Version](<https://www.cancer.gov/types/retinoblastoma/patient/retinoblastoma-treatment-pdq>)

- [Tests and next steps for retinoblastoma - NHS](<https://www.nhs.uk/conditions/retinoblastoma/tests-and-next-steps/>)

- [Symptoms of retinoblastoma - NHS](<https://www.nhs.uk/conditions/retinoblastoma/symptoms/>)

General health education; not a substitute for individualized clinical assessment.

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