Oh Ina! This must be so difficult for you! Im sure you are very worried and with only getting small bits of info you cant put them all together.

What it sounds like to me is that her original mandibulectomy did not get clear margins and the cancer came back. Its only been a few months since her big surgery and its already visible. To me that means they missed some. Thats why usually radiation will follow surgery to ensure it kills all the remaining cancer cells. From what you wrote it sounds like the skin is what will be removed and she will have graphs from other areas of her body. Since chemo alone doesnt kill oral cancer just sometimes it will shrink it, the cancer grew like crazy when the chemo treatments were finished. I hope the upcoming surgery will eliminate all the cancer this time.

Best wishes!