B-scan ultrasonography of a 2-year-old with leukocoria reveals a solid intraocular mass with focal highly reflective echoes that persist when gain is reduced, accompanied by acoustic shadowing behind these echoes. The most likely diagnosis is:

• A Persistent fetal vasculature
• B Coats disease
• C Retinoblastoma with calcification ✓
• D Toxocariasis granuloma

Explanation

Intralesional calcification is the sonographic hallmark of retinoblastoma: calcium produces very high amplitude echoes that persist at low gain settings with orbital shadowing behind them. Persistent fetal vasculature shows a retrolental stalk without a solid mass, Coats disease shows diffuse subretinal exudation rather than a calcified mass, and toxocariasis granuloma lacks characteristic calcification. Recognizing calcification on B-scan also helps differentiate retinoblastoma from simulating lesions.

Reference: Kanski's Clinical Ophthalmology, 9th ed.

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Written and medically reviewed by the StethoPrep medical team.