I appreciate this is slightly off the advice you were seeking but it might offer a bit of help.
The key is in what kind of cyst it is. I have two cysts on my head and have had them for a long time. They run in my family and the past couple of years (I swear they have gotten larger during/after my being pregnant) they got large enough that they were bothering me. In my case they are called sebaceous cysts. They are completely benign-they start as like a blocked duct in a hair follicle and are very common. I was told the same thing-benign and if I wanted, I could get them removed, which I'm doing in about a week. All of this is with the NHS, not private.
It is my understanding that anytime they remove things like this a biopsy will occur-so it's not always necessary to do a biopsy, as the tissue will be tested. Again, it depends on what type of cyst it is. I should also add that I had skin cancer. My cyst was looked at by a GP before I had skin cancer and after it had gotten bigger and the same response-I was told it had no bearing on it.