Review of trilateral retinoblastoma: insights into its origin and approaches to its management

Purpose. To examine the histopathogenesis, treatment modalities and survival in 71 cases of trilateral retinoblastoma (TRb) reported in the world literature. Methods. We reviewed all cases of TRb reported from 1977-1996. Results Histopathologic findings demonstrate primitive neuroectodermal tumors in 55% of cases. Varying degrees of photoreceptor differentiation were seen in 45% of cases. Autopsy, histopathologic and radiologie examination do not reveal a definitive origin, although "pinealoblastoma" was often the diagnosis reported. Histopathologic evidence of subependymal\ependymal craniospinal seeding was seen in 65% of cases. TRb is uniformly fatal with an average survival of 11.2 months. Therapy included: 1) radiation, 2) systemic chemotherapy, and 3) surgical resection/ craniotomy in combination with radiation and/or chemotherapy with survival of 5.4, 25.8 (4 children alive at time of report), and 16.8 months (2 children alive), respectively. Patients receiving platinum-based systemic chemotherapy in combination with intrathecal chemotherapy and neural axis radiation demonstrated an average survival of 15.5 months. Conclusion. TRb more likely arises from a germinal layer of predisposed primitive subependymal neuroblasts that are not necessarily destined for pineal or photoreceptor differentiation. Recent success with platinum-based ocular chemoreduction together with the above findings, suggests that routine CNS imaging and aggressive platinum-based chemotherapy, intrathecal chemotherapy, radiation and surgery should be considered.