Trilateral retinoblastoma with unilateral eye involvement.

Retinoblastomas (RB) are the main forms of intraocular tumor in childhood, with a worldwide incidence of 1 case per 15,000 to 20,000 live births. Trilateral RB (RBT) is a rare combination of unilateral or bilateral RB with a midline intracranial neoplasm of neuroblastic origin, usually found in the pineal region or the suprasellar region, presenting variable incidence of 0.5% up to 6% among patients with RB.