Retinoblastoma

The international Retinoblastoma Staging System(1-3)(13) Stage 0: • Eye has not been enucleated and no dissemination of disease. Stage I: • Eye enucleated, completely resected histologically. Stage II: • Eye enucleated, microscopic residual tumor. Stage III: • Regional extension III A: Overt orbital disease III B: Preauricular or cervical lymph node extension Stage IV: • Metastatic disease. IVa: Hematogenous metastasis (without CNS involvement) IVa1: Single lesion IVa2: Multiple lesions IVb: CNS extension (with or without any other site of regional or metastatic disease) IVb1: Prechiasmatic lesion IVb2: CNS mass IVb3: Leptomeningeal and CSF disease High risk pathology features (1-3) (13) • The main high-risk feature is extension of the tumour in the optic nerve to the margin of the surgical resection. • Post laminar optic nerve invasion; • Involvement of anterior segment; • Massive invasion of choroid > 3mm; • Invasion of sclera; • Extra scleral tumour extension. • Any degree of concomitant choroid and optic nerve involvement.