Malignant melanoma developed at about the end of the first year of life in an infant boy. The tumor arose in a giant congenital pigmented nevus that had been treated with betamethasone valerate. Multiple metastases developed, and death supervened at the age of 28 months.
Penman HG, Stringer HCW. Malignant Transformation in Giant Congenital Pigmented NevusDeath in Early Childhood. Arch Dermatol. 1971;103(4):428-432. doi:10.1001/archderm.1971.04000160078012