My DS(14) had a thyroglossal cyst when he was a baby, the consultant originally decided that he was too young for the operation. The cyst was huge and as a result DS had delayed speech due to the pressure cyst was putting on his vocal cords.
To cut a long story short when he was 2.5 the cyst popped while we were in Florida. Was really not very pleasant and poor DS was in a lot of pain.
On arrival back at the UK and under a different hospital, as we had moved, the consultant decided that DS needed to go straight in to have op.
Op was very straight forward and site was quite small. However DS was very scared when he came round and pulled out drain, pulling out stitches and making a mess of wound. This also meant DS and I had an overnight stay in the hospital, which was unplanned.
It took 6 weeks to heal and we had to have nurse visit to change dressing every day - this was far worse than the op to be honest and I think caused far more issues to DS than op would have.
DS has very small scar now, which is in neck crease and really only obvious to us as we know that it is there.
Have you been told how soon they want to operate, and what they expect to do whilst in theatre?
The first consultant had told us operation would be much worse than it finally was (Was talking about slicing him from ear to ear and pulling out his tounge to reach cyst, This was really unnecessary and DS's scar is only between 1-2 inches long!!)
DS was left for well over a year until surgery was necessary, and apart from the speech delay had no further worries.
However knowing how nasty DS's cyst went when it burst,and how much pain he suffered it may be wise to get it sorted before it got this far.