If you have a competent doctor, they should give something so that your child should not feel much if any discomfort. They should make sure to adjust the dosage of any medication based on your child's age and weight. A relative of mine had two cysts ingrown from the area of the ears & she had them removed under anesthesia I believe when she was older than your son, but could be a totally different kind of cyst. Did they say if it was cyst on his thyroid, since you mentioned the neck?
Thanks for the reply, i dont know what kind of cyst , the doctor just did ultra sound, and than asked for biopsi, my concern is that it might be cancer, i wonder how much the chance is that this cyst is a cancer,
The doctor evidently did not communicate as well as they should have and needs to tell you why he/she feels a biopsy is warranted and should also tell you what the cyst is on exactly. Of course many biopsies can turn out benign (non-cancerous), but if you are armed with more info from your doctor, you may be able to research better as to how often the cyst with the properties your child has turns out to be cancer. If you belong to the Lord, entrusting your son into His loving, completely in control care can help with the anxiety.
I think the reason they waited on my relative until she was a older than your son for her ingrown cysts was to do with size of face. Her cysts were growing into her face from the ears, I believe.