Histopathologic risk factors in retinoblastoma in India.

Context: The presence of histopathologic risk factors is associated with development of metastasis in a patient with retinoblastoma. Adjuvant chemotherapy administered to such patients decreases the risk of metastasis.
Objective: To analyze the incidence of histopathologic risk factors in our patient population and the clinical predictors of such risk factors.
Design: This is a retrospective case series, with review of clinical data and histopathologic slides, in 142 consecutive eyes enucleated for retinoblastoma between 1996 and 2002.
Results: Histopathologic risk factors were present in 54.2% of 142 eyes enucleated for retinoblastoma and included infiltration of iris (7%), ciliary body (9%), choroid (40%), optic nerve lamina cribrosa (11%), retrolaminar optic nerve (17%), optic nerve to the line of transection (8%), sclera (9%), and extrascleral structures (6%). On univariate analysis, histopathologic risk factors correlated with age greater than 24 months at presentation and with glaucoma and iris neovascularization at presentation. On multivariate logistic regression analysis, age greater than 24 months and iris neovascularization correlated with infiltration of the choroid, while iris neovascularization correlated with infiltration of the retrolaminar optic nerve.
Conclusion: Histopathologic risk factors are present in a significant proportion of patients enucleated for retinoblastoma and have identifiable clinical predictors.