[Retinoblastoma]

Hereditary retinoblastoma is different from non-hereditary retinoblastoma in the following ways. It has a germinal mutation of Rb gene located in 13q14. Its inheritance is autosomally dominant with 80% penetrance. Retinal tumors are present usually multiply (average number is three) in both eyes. The patients are found at a younger age than those non-hereditary retinoblastoma. About 5% of them are accompanied by a pineal tumor or paracellular neuroectodermal tumor, in such cases they are called trilateral retinoblastoma. Secondary malignancies such as osteosarcoma and rhabdomyosarcoma are more frequent, and they are the main causes of death of patients with hereditary retinoblastoma. Considering these facts, education of patients and their family members and development of new modalities of treatment for preserving eyeballs without inducing secondary malignancies are important.