Intracranial malignancy in patients with bilateral retinoblastoma

Tumors from two patients with bilateral retinoblastoma and intracranial malignancies were studied from a clinical, histopathological, and an immunohistochemical standpoint. An antiserum derived against tissue cultured Y-79 retinoblastoma cells was utilized in order to examine the surface and cytoplasmic antigens of the two brain tumors, histopathologically diagnosed as an embryonal cell carcinoma (case 1), a pinealoblastoma (case 2), and one ocular retinoblastoma. The two brain tumors reacted with the antiserum to different degrees. In comparison, the ocular tumor reacted strongly. None of the tissues examined were found to contain retinal S- or P-antigen. The concept of retinoblastomas arising de novofrom the pineal gland and the association of intracranial malignancy occurring in retinoblastoma is stressed. The antigenic and immunologic relationships between normal retina and pineal gland and retinoblastoma, neuroblastoma, and pinealoblastomas are discussed.