In 1872 a Brazilian ophthalmologist performed an enucleation in a young boy with retinoblastoma. This boy survived and married a woman without any family history of cancer. The couple had two daughters with bilateral retinoblastoma also seen by the same ophthalmologist, Hilário de Gouvêa. This case became the first documented report of a family with retinoblastoma in more than one generation. Here we examine the life of de Gouvêa and his contribution which raised the possibility that cancer had a genetic basis. We discuss how de Gouvêa's mind had been prepared to realize the importance of this observation. We attempt to define the conditions that allowed not only his discovery, but also the report of the findings and a dogged pursuit for credit over many years in a country which had virtually no research tradition and was still grappling with its recent colonial history.