Intracranial tumors in children with retinoblastoma (RB) were first described by Jensen and Miller in 1971 as a primary focus of RB, but the term ‘trilateral retinoblastoma (TRB)’ was first coined by Bader et al. in 1982 to describe patients with pineoblastoma and retinoblastoma. Ectopic intracranial tumors (trilateral retinoblastoma or TRB) comprised of embryonal cells with photoreceptor differentiation occur in children with the genetic form of RB, either inherited or sporadic. Children with familial retinoblastoma are at greater risk for TRB than children with new germline mutations. Surveillance with MRI in children with bilateral and unilateral familial RB can detect intracranial tumors at an early stage when they are more likely to be cured with aggressive multimodal therapy. Pineal cysts detected on MRI should not be confused with true neoplasms; experienced neuroradiologists should review questionable scans. Markers for photoreceptor differentiation or a transcription factor (CRX) may be useful in diagnosing intracranial and potentially metastatic disease in RB patients.