You had no way of knowing that the little lad was really ill.My sister nannies for a little girl with a brain tumour & despite all her family being concerned about her health & having Drs in the family,it was undiagnosed for a long,long time.Apparently they are so rare that it isn't the 1st thing to come to mind,my GP says that he will probably only see one case throughout his working life.
Anyway,this little girl's tumour isn't malignant,Thank God,but can't be removed.18 months on,after treatment to shrink it,she is like any normal toddler & has come on in leaps & bounds.So there is every reason to be optomistic for your friends son.