A 15-year-old girl is referred with leukocoria in the right eye. Ultrasonography shows intraocular calcification. Retinoblastoma is suspected. The most important indicator of high risk for metastasis after enucleation based on histopathological examination is:

• A Massive choroidal invasion (>3 mm depth) combined with post-laminar optic nerve invasion ✓
• B Choroidal invasion <3 mm without scleral extension
• C Retinal detachment with subretinal seeding
• D Vitreous seeding with calcification

Explanation

Histopathological high-risk features for metastatic retinoblastoma include: post-laminar optic nerve involvement, massive choroidal invasion (>3 mm), scleral extension, and surgical margin positivity. The combination of massive choroidal invasion (significant vascular access) and post-laminar optic nerve invasion (subarachnoid space access) is the most ominous combination. These patients receive adjuvant systemic chemotherapy post-enucleation. Subretinal seeding and vitreous seeds are intraocular high-risk features but less predictive of metastasis than optic nerve/choroidal breach.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.