Retinoblastoma.

Retinoblastoma is the most common primary intraocular malignancy of childhood. It typically presents with leukocoria or strabismus. In later stages of the disease, the child may exhibit proptosis, buphthalmos, or hypopyon. The pathognomonic molecular aberration is a loss of function mutation in the RB1 gene on chromosome 13q. The degree of tumor involvement within the eye is defined by its group. Grouping was historically done with Reese-Ellsworth System. Recent therapeutic advances have led to the development of a new grouping system, the International Classification of Retinoblastoma (ICRB). In cases of extraocular extension and metastatic disease, the degree of tumor involvement outside of the eye is defined by its stage. Retinoblastoma is staged using the International Retinoblastoma Staging System (IRSS). Children with intraocular retinoblastoma have an excellent overall and ocular survival. In order to avoid the morbidity of enucleation and external beam radiation, treatments for isolated intraocular retinoblastoma have progressively moved toward targeted local modalities. Patients with extraocular involvement, such as those with trilateral retinoblastoma, have a poorer prognosis. The majority of these higher stage patients are now able to be cured with combination chemotherapy.