OCT Imaging of Schlemm's Canal Invasion in a Retinoblastoma Patient

Aqueous seeding in retinoblastoma: Classification and clinicopathological correlation

PURPOSE

To correlate clinical types of aqueous seeds with histopathological characteristics in primarily enucleated eyes with retinoblastoma (RB).

DESIGN

Retrospective study PARTICIPANTS: Twenty-five patients with RB METHODS: Clinicopathological correlation of aqueous seeds in 25 eyes that underwent primary enucleation and had evidence of aqueous seeds MAIN OUTCOME MEASURES: Histopathological characteristics of aqueous seeds RESULTS: All 25 enucleated eyes were classified as group E RB based on International Classification of Intraocular Retinoblastoma. Clinically, type 1 aqueous seeds were noted in 9 (36%), type 2 in 8 (32%), and type 3 in 8 (32%). Based on histopathology, type 1 seeds were individual tumor cells admixed with macrophages and non-viable tumor cells; type 2 seeds were spheres and are classified into two subtypes a) Spheres without central necrosis containing solid clusters of tumor cells b) Spheres with central necrosis containing central core of necrotic cells surrounded by viable tumor cells; and type 3 seeds were tumor cells admixed with macrophages and RBCs that sediment into angle. Aqueous seeding involved both anterior (n=25; 100%) and posterior chambers (n=18; 72%). Significant intraocular tissue (Schlemm's canal, trabecular meshwork, ciliary body, choroid, optic nerve, sclera) infiltration of RB was noted in 23 (92%) cases. Compared to type 1 and 2 seeds, patients with type 3 seeds were more commonly associated with ciliary body infiltration (41% vs 88%; p=0.04). Over a mean follow-up period of 57 months (median, 49 months; range, <1 to 175 months), metastasis and death was noted in 3 (12%) patients.

CONCLUSION

Similar to vitreous seeds in RB, aqueous seeds have three distinct histopathological types. Posterior chamber seeds are noted in 72% cases presenting with anterior chamber seeds indicating the need for treatment of both the chambers whenever conservative treatment is attempted in suitable cases. Most (92%) cases with primary aqueous seeding are associated with other high-risk histopathology features, suggesting a cautious approach for conservative management in these cases.

Aqueous seeding in intraocular retinoblastoma: A review

The management of retinoblastoma is complex. With increasing treatment modalities and increasing experience with each treatment modality, the globe salvage rates have drastically improved with time. Aqueous seeding in an eye with retinoblastoma is classified as group E based on International Classification of Intraocular Retinoblastoma, and most group E eyes were enucleated a decade earlier. Newer modalities of treatment have improved the globe salvage rates in group E eyes including those with aqueous seeding. Various globe salvage treatment modalities attempted for the management of aqueous seeds include external beam radiotherapy, plaque radiotherapy, intra-arterial chemotherapy, periocular chemotherapy, intravitreal chemotherapy and intracameral chemotherapy. Of all treatment modalities, intracameral chemotherapy holds promise for the management of aqueous seeds in selected patients, but it should be done with the utmost care by a trained ocular oncologist. Enucleation is still the preferred modality of treatment for eyes with advanced retinoblastoma and anterior segment invasion. This review focuses on the current evidence on aqueous seeding, highlighting the pathogenesis, classification, clinical presentation, treatment and outcomes.

Current Indications of Secondary Enucleation in Retinoblastoma Management: A Position Paper on Behalf of the European Retinoblastoma Group (EURbG)

Simple Summary

Although secondary enucleation (SE) is the treatment of choice for retinoblastoma eyes that did not respond favorably to conservative therapies, clear criteria for its indication are, however, currently missing. In this position paper on behalf of the European Retinoblastoma Group (EURbG), we discuss the available literature on SE, including its influence on metastases rate and survival, and propose guidelines to assist decision-making to interrupt eye-preserving therapies depending on the availabilities of advanced diagnostic and therapeutic modalities. Absolute indications to SE may be restricted to eyes with refractory tumor activity resisting all salvage treatments or eyes under apparent tumor control but no visual potential and irreducible complications. In contrast, eyes with an obscured optic nerve head and/or ocular complications amenable to specific surgical or medical management can be considered relative indications, provided that appropriate follow-up can be implemented and that parents are fully aware of a residual risk.

Abstract

Secondary enucleation (SE) puts an irreversible end to eye-preserving therapies, whenever their prolongation is expected to violate the presumed state of metastatic grace. At present, it must be acknowledged that clear criteria for SE are missing, leading to empiric and subjective indications commonly related to disease progression or relapse, disease persistence masking the optic nerve head or treatment-related complications obscuring the fundus view. This absence of evidence-based consensus regarding SE is explained by the continuously moving frontiers of the conservative management as a result of diagnostic and therapeutic advances, as well as by the lack of studies sufficiently powered to accurately stratify the risk of metastasis in conservatively treated patients. In this position paper of the European Retinoblastoma Group (EURbG), we give an overview of the progressive shift in the indications for SE over the past decades and propose guidelines to assist decision-making with respect to when SE becomes imperative or recommended, with corresponding absolute and relative SE indications. Further studies and validation of biologic markers correlated with the risk of metastasis are expected to set more precisely the frontiers of conservative management and thus consensual criteria for SE in the future.