LAUSR

To study the high-risk histopathology features of retinoblastoma based on age at primary enucleation. Retrospective study of 616 patients. The mean age at presentation and primary enucleation for retinoblastoma was 34 months (median, 28 months; range, <1–455 months). Of these cases, 128 (21%) were aged ≤1 year, 149 (24%) were in the age group of 1–2 years, 117 (19%) in 2–3 years, 104 (17%) in 3–4 years, and 118 (19%) were >4 years of age at the time of enucleation. Bilateral retinoblastoma (34%; p < 0.0001) and buphthalmos (20%; p < 0.0001) were more common in children ≤1 year of age. Anterior chamber pseudohypopyon (15%; p < 0.0001) and vitreous seeds (53%; p < 0.0001) were more common in children aged >4 years. Based on 8th edition American Joint Committee on Cancer staging system, pT3 was less common in children ≤1 year of age (13%; p < 0.001). Based on histopathology, 38% patients had high-risk features including 24% children aged ≤1 year, 42% in the age group of 1–2 years, 34% in 2–3 years age group, 45% in 3–4 years age group, and 48% patients were >4 years of age. Post-laminar optic nerve infiltration (6%; p = 0.02) and massive choroidal infiltration (9%; p = 0.04) was least common in children ≤1 year of age. Over a mean follow-up period of 52 months (median, 36 months; range, <1–218 months), systemic metastasis and death occurred in 9% patients despite adjuvant systemic chemotherapy. The predominant high-risk histopathology feature of retinoblastoma varies with age at primary enucleation.