Trilateral retinoblastoma. Report of two cases.

Two children had bilateral retinoblastoma and a morphologically similar intracranial neoplasm localized to the region of the pineal gland as shown on computed tomography and at postmortem examination. The first child's intracranial malignant neoplasm produced symptoms that indicated its probable presence when the ocular tumors were first diagnosed. With the second child, there was a latent period of more than three years between the diagnosis and initial management of the ocular neoplasms and the onset of symptoms from the pineal tumor. We diagnosed both cases as trilateral retinoblastoma, which in our experience is a relatively frequent cause of mortality in patients with heritable retinoblastoma.