Context: In eyes enucleated for retinoblastoma, presence of histopathologic high-risk factors is associated with a higher risk of local recurrence and systemic metastasis.
Objective: To evaluate histopathologic features in children with retinoblastoma in our population and establish relationship between age, tumor differentiation, and high-risk features.
Design: Retrospective histopathologic analysis of 609 consecutively enucleated eyes for advanced intraocular retinoblastoma during a 10-year period. A nonparametric test was used to establish relationship between age, differentiation, and high-risk features.
Results: Poorly differentiated retinoblastoma presented in 80.3% and well-differentiated in 19.7% of eyes. Well-differentiated tumors presented earlier (median 1.2 years) than poorly differentiated tumors (median 2.5 years) (P < .001). One hundred fourteen eyes (18.7%) had 1 and 138 (22.7%) had at least 2 high-risk histopathologic factors. Invasion of anterior chamber was found in 10.0%, iris in 10.7%, ciliary body in 6.7%, sclera in 13.7%, massive choroid in 24.6%, postlaminar optic nerve in 16.1%, resected margin of the optic nerve in 7.4%, and extrascleral tissue in 4.1% of eyes. Extensive necrosis was seen in 31.0% of eyes. Poorly differentiated tumors were significantly associated with presence of more than 1 high-risk histopathologic feature (P < .001) and extensive necrosis (P < .001).
Conclusion: Poorly differentiated tumors present at a later age and are associated with presence of multiple high-risk factors and extensive necrosis. In our population, high-risk histopathologic factors are present in a significant number of eyes. Because we have included only primarily enucleated eyes, this could truly represent the distribution of high-risk histopathologic factors in children with retinoblastoma.