Occurs in 1/12,000 live births.
Most common eye tumor in children
No race or gender predilection.
75% unilateral, nonhereditary. Age of unilateral dz: 18-24 months
25% bilateral, hereditary. Median age of b/l dz: 1 y/o
>90% present before 5 y/o
Gene: RB1, on long arm of 13, acts as a tumor suppressor gene. Two hit model.
Path: extraocular extension may occur through choroid or optic nerve invasion.
Screening: If (+) family hx, then do routine neonatal opthalmologic screening. Otherwise presents with white pupillary reflex (leukocoria); a red reflex is not present in a flash photograph of the face, or during exam. Strabismus is often the initial complaint. Advanced disease: orbital inflammation, hyphema, pupil irregularity. Pain, if secondary glaucoma present.
Dx: EUA by opthalmologist. Orbital US and CT to eval intraocular extent and extraocular spread. MRI not for routine exam. Bone scan, CSF, BM sampling only if otherwise indicated.
DDx of intraocular tumor: hyperplastic primary vitreous, Coat dz, cataracct, visceral larva migrans, choroidal coloboma, ROP.
Tx: aim for cure and preserve vision.
Primary enucleation no longer routine.
Unilateral dz: if no potential for useful vision, enucleate. If feasible, small tumors: laser photocoag or cryotherapy. with careful f/u. Larger tumors: multiagent tx i.e. carboplatin, vincristine, etoposide. If failure, external beam irradiation or brachytherapy (may result in sig orbital deformity and second cancer).
B/L dz: enuclation of more severe eye and irradiation of remaining eye. May try to salvage both eyes with effective chemo. Depending on chemo response, local control w/ laser photocoag, cryotherapy, hyperthermia. Large residual tumor masses: external radiation or brachytherapy. Nonresponsive/recurrent: enucleation.
Px: after primary enucl of unilat intraoc tumor, cure rate>90%. Early reports of pt tx w local tumor ablation w/wo chemo suggest potential for equally impressive survival w some retention of vision. If RB1 mut, sig risk for 2nd cancer, esp if rad tx used. Other rad relations complic: cataracts, orbital growth deformity, lacrimal dysfunction, late retinal vascular injury.