Seven cases of trilateral retinoblastoma.

Of 245 consecutive children with retinoblastoma referred to the Oncology Service at the Wills Eye Hospital between January 1974 and August 1988 and followed up for three months to 15 years, seven (3%) developed midline intracranial malignancies consistent with the diagnosis of trilateral retinoblastoma. Six of the seven had bilateral retinoblastoma, and four had a family history of retinoblastoma. The time of diagnosis of retinoblastoma varied between five months after the intracranial tumor was diagnosed and four years before the intracranial tumor was diagnosed. The midline intracranial malignancies were pineal tumors (five cases), suprasellar neuroblastoma (one case), and a parasellar undifferentiated calcified mass (one case). Despite control of the intraocular tumors, five of the seven children have died of the intracranial tumors.