Leukocoria in a 3-Year-Old: What Not to Do
A 3-year-old boy is brought by his mother, who noticed a white pupillary reflex in photographs about 2 months ago; it is now visible in room light. He was born at 38 weeks with no prematurity, no trauma, and no family history of eye disease. He fixes and follows with the left eye but resists occlusion of the right eye. The right eye has a 4 mm white mass behind the lens, dilated iris vessels, intraocular pressure 26 mmHg by Perkins tonometry, and corneal diameter 11 mm; there is no hyphema. B-scan shows a 12 × 10 mm intraocular mass with calcification and no retinal detachment; axial length is 21 mm. The left eye is normal. The referring optometrist has booked examination under anesthesia in 6 weeks and asks whether fine-needle aspiration should be done at that visit to confirm the diagnosis.
1. What is your differential diagnosis and immediate plan? Address the optometrist's request for fine-needle aspiration.
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Differential. Retinoblastoma is the priority. Alternatives include Coats disease, persistent fetal vasculature, toxocariasis, congenital cataract, retinal dysplasia, and medulloepithelioma. The calcified mass, dilated iris vessels, and raised pressure strongly favor advanced retinoblastoma.
Why not FNA. Fine-needle aspiration is contraindicated when retinoblastoma is possible. It can seed tumor along the needle tract, cause intraocular hemorrhage and extraocular extension, and convert a potentially curable intraocular tumor into disseminated disease. Diagnosis is clinical and confirmed at examination under anesthesia, not by biopsy. Diagnostic vitrectomy is also avoided for the same reason.
Immediate plan. Refer the same day to an ocular oncology service; do not wait 6 weeks. Examination under anesthesia should occur within days and includes fundoscopy of both eyes, measurement of IOP and axial length, and documentation of tumor size and seeding. Arrange contrast MRI of orbits and brain to assess optic nerve and pineal involvement. Do not start treatment before oncology assessment unless there is acute pain or perforation. Explain to the parents that the eye may not be salvageable but that the priority is life and systemic cure.
2. What systemic work-up, genetic evaluation, and family counseling would you arrange, and why is the 6-week delay unacceptable?
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Systemic and genetic work-up. All children with retinoblastoma need RB1 testing, ideally on blood and tumor tissue. About 40% carry a germline mutation; this affects siblings, future children, and risks of second cancers. A genetic counselor should see the family. Siblings require screening from birth; parents may need fundus examination if a germline mutation is found. MRI brain and orbits is standard; lumbar puncture and bone marrow biopsy are reserved for high-risk features such as optic nerve or choroidal invasion, not routine.
Explaining urgency. Retinoblastoma can double in volume within weeks. A 6-week delay may allow the tumor to fill the eye, seed the vitreous, raise pressure, and require enucleation rather than globe-sparing therapy. It also increases the risk of optic nerve extension. Tell the parents this is a life-threatening diagnosis, not a cosmetic problem, and that the 6-week appointment is unsafe. Give them written emergency contact details and ensure the referral is confirmed by telephone. Emphasize that the child is otherwise well and that coordinated care gives good survival in high-income settings.