Orbital extension of retinoblastoma: a clinicopathological study.

We have studied all cases of orbital extension of retinoblastomas at the Edward S. Harkness Eye Institute in New York since 1925. Only 9.4% of the patients lived more than 2 years after diagnosis. Orbital retinoblastoma is frequently associated with systemic metastases. We emphasize the significance of massive choroidal involvement and periemissarial extension. Careful handling of the enucleation specimen at the time of surgery and during histologic preparation is important to avoid cell spillage and artifacts. Treatment should be early, multidisciplinary and include adjuvant chemotherapy.