Age-dependent variation of doubling times in malignant disorders: why are the doubling times of tumours in childhood shorter than in adulthood?

In vivo growth of retinoblastoma in a newborn infant

Retinoblastoma is a rare malignancy of the retina seen exclusively in children. It is known to cause rapid growth inside the eye and hence treatment should be started as soon as it is diagnosed. We report a case in a five-day-old infant in whom treatment (chemotherapy) was delayed by a month due to high bilirubin levels secondary to physiological jaundice, which gave us the unique opportunity to measure the growth of the tumor over a month. This case emphasizes that immediate treatment is warranted once this rare disease is diagnosed.