Snapshot A 2-year-old boy presents to his pediatrician for strabismus. Family history is notable for osteosarcoma in his father. Physical examination is notable for strabismus and bilateral leukocoria. He is referred to a pediatric ophthalmologist for further evaluation. Introduction Overview a primary intraocular malignancy arising from the retina 2 forms login to view 6 more bullets Epidemiology Incidence most commonly affects children (< 5 years of age) ETIOLOGY Pathophysiology RB1 gene encodes a nuclear protein, retinoblastoma, that serves as a tumor suppressor located in chromosome 13 does not allow the cell cycle to proceed from the G1 to the S phase login to view 1 more bullet loss of the RB1 gene dysregulates the cell cycle and results abnormal cellular proliferation "2-hit hypothesis" there are 2 Rb alleles that encode the tumor suppressor login to view 2 more bullets Associated conditions osteosarcoma Presentation Symptoms visual loss Physical exam leukocoria loss of/abnormal red reflex strabismus nystagmus Imaging Ocular ultrasonography indication may be performed prior or during ophthalmologic examination under anesthesia login to view 1 more bullet Optical coherence tomography indication performed during ophthalmologic examination under anesthesia provides high-resolution images that can detect small tumors, can serve as a screening tool, and identify tumor recurrence MRI Brain and orbit indication imaging study of choice helps determine potential optic nerve involvement, determine the size of the tumor, and if there is an associated intracranial tumor Studies Ophthalmic evaluation under anesthesia indication newly diagnosed leukocoria in a child component of evaluation of retinoblastoma findings chalky and off-white retinal mass login to view 1 more bullet Biopsy contraindicated because of the risk of tumor seeding Genetic testing performed in all cases Differential Cataract differentiating factor ophthalmologic examination will demonstrate opacification of the lens Treatment Medical local and systemic chemotherapy indication login to view 1 more bullet Surgical laser photoablation indication login to view 1 more bullet radioactive plaques indication login to view 1 more bullet cryotherapy indication login to view 1 more bullet enucleation indication login to view 1 more bullet Complications Metastatic disease Blindness Prognosis Deadly if not treated the tumor expands to fill the eye and destroy the globe > 95% survival with treatment