Leukocoria (white pupillary reflex) in a 2-year-old child has a differential diagnosis. Which of the following causes can be distinguished from retinoblastoma MOST reliably by the presence of calcification on CT scan?

• A Retinoblastoma ✓
• B Persistent fetal vasculature (PFV)
• C Toxocara endophthalmitis
• D Coats disease

Explanation

Calcification within the globe on CT scan is highly characteristic of retinoblastoma (seen in >90% of cases). The calcium deposits appear as dense flecks or nodules within the intraocular tumour mass. Persistent fetal vasculature causes microphthalmia with a retrolental fibrovascular mass but typically lacks calcification. Toxocara granuloma may rarely calcify but the clinical context (eosinophilia, pet exposure) and serology differentiate it. Coats disease shows exudative retinal detachment with subretinal lipid/protein but no calcification. Thus CT demonstrating intraocular calcification in a 2-year-old with leukocoria virtually confirms retinoblastoma.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.