Histopathologic analysis of 232 eyes with retinoblastoma conducted in an Indian tertiary-care ophthalmic center

PURPOSE: To study the histopathologic features of 232 enucleated eyes with retinoblastoma. MATERIALS AND METHODS: Two hundred thirty-two enucleated eyes with retinoblastoma in a tertiary-care institute from 1982 to 2001 were reviewed. Data were collected and analyzed about the type of growth and the presence or absence of vitreous or subretinal seeding, rosettes and fleurettes, necrosis, calcification, iris neovascularization, and invasion of the anterior chamber, iris, choroid, optic nerve, and sclera. Choroidal invasion was graded using a new system. Results were analyzed for statistical significance. RESULTS: The endophytic growth pattern was common in 118 (51%) of the eyes. Vitreous seeds were present in 109 (47%) of the tumors, 23 (10%) of the tumors had subretinal seeds, and 14 (6%) of the tumors had both. Poorly differentiated tumors were present in 134 (58%) of the eyes. Iris neovascularization was noted in 71 (31%) of the eyes and choroidal invasion was observed in 78 (34%) of the eyes. Of these 78 eyes, full-thickness (stage 4) choroidal invasion was present in 51 (65%). Optic nerve invasion was observed in 75 (32%) of the eyes, of which prelaminar involvement occurred in 40 (53%) and postlaminar involvement occurred in 22 (29%). CONCLUSION: A higher incidence of choroidal and optic nerve infiltration was noted among Asian Indian children than among children from the West. This could be due to delayed diagnosis or to a difference in the biological behavior of tumors occurring in the Asian Indian population.