Hi – I went through this as a child of similar age! The operation would have been okay except for the fact my mother had said it was okay for students to be present. I was awake and could have done without hearing what all the surgical equipment was for. Luckily my first mole (the largest I had removed with two colours and jagged edges - it was so big) turned out to be benign despite growing a lot (hence the concern). Since then I've had others removed which have been anything from mildly to severely dysplastic. It is very important for you to keep your son's mole out of the sun while waiting to be seen and to be generally sun aware. There is good advice on this site, although the hospital have told me to be even more cautious because of my history of moles. I had a lesion out this summer that was itching and tingling (really bothering me). I was lucky as it was again dysplastic not cancerous. So the mole needs to be seen but even if doctors decide to remove it that doesn't mean it is cancerous. The more likely scenario statistically is that it isn't. 

Am going to issue a plea from the child in me, please don't authorise students. My mother acted with good intentions no doubt, but it was too much for me. Others might have a different view on this, but it really is etched in my mind as something I would rather not have had to deal with.

Please try and stop worrying and all you need to say to your child is that the doctors need to take the mole out to stop it itching. No need to cause undue concern as the odds are on your side here all the more so given your son's age. I certainly wanted my itchy/tingly/nasty sensation mole out asap. Luckily for me my most recent excision was done the same day. Sending you both good wishes.