The Practical Management Of Retinoblastoma

Abstract

Retinoblastoma is inherited as an autosomal dominant characteristic. A sporadic unilateral case will transmit the disease to 10 to 20 percent of his children, whereas a sporadic bilateral case will pass it on to nearly 50 percent of his progeny. When a family history is present, retinoblastoma is particularly apt to be bilateral. All retinoblastomas may be considered to be germinal mutations, albeit of highly variable manifestation. When one child with retinoblastoma is born to normal parents with no family history of the disease, there is a 4 percent chance that future siblings will be affected. Retinoblastoma cells closely resemble primitive retinal cells that are destined to become receptor cells. The diagnosis is difficult when the tumor itself is not ophthalmoscopically visible. Typical calcification and seeding are almost pathognomonic signs. The fourteen conditions most commonly confused with retinoblastoma are briefly outlined. The current results in 192 cases are presented. Pedigrees of the familial cases are appended as a reservoir for future calculations, since they are relatively rare. It is easy to imagine that some local factor in a particular tumor could cause it to regress spontaneously. There is one example of a bilateral spontaneous regression in the literature and there is one well-documented case in our own series. This would lead us to believe that there may be some systemic factor, immunological or otherwise, that allows tumors in certain individuals to be destroyed spontaneously. These patients deserve particular study since the behavior of their tumors could provide some clue to a new therapeutic approach.