Impact of secondary IDCH and nodal involvement at diagnosis. Both (A) secondary IDCH and (B) nodal involvement at diagnosis were associated with inferior median and 72-month survival. (C-D) Subgroup analysis excluding the 7 pediatric patients aged <18 years showed similar findings. Separate analysis of pediatric patients was underpowered but there were no deaths in these patients during the analysis time of 72 months after excluding pediatric patients from the analysis.