There are numerous recognized causes for fever of unexplained origin in childhood but these have not included retinoblastoma. A single case which is probably unique points to this tumor as the etiology of continued high fever. Final diagnosis necessitated extensive studies to exclude coincidental or complicating conditions.
Hearey CD, Daley TJ, Shaw EB. Prolonged Fever From Unusual Cause (Retinoblastoma). Am J Dis Child. 1972;123(1):51–52. doi:10.1001/archpedi.1972.02110070101014