Mohs surgery is a wonderful procedure that has over a 99% cure rate. I don't know when you had your original diagnosis, but even if it's been a bit the likelihood of it spreading to the skull or metasticizing like you are describing is pretty much impossible. What it most likely would be is that the roots of the cancer itself may have spread a bit more underneath the skin. Even with this, it's still very treatable and ok.
"This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."
Metastasis of non-melanoma skin cancer can occur but is very uncommon. Mohs surgery has the lowest recurrence rate and also leaves the smallest possible wound. That's a win-win. Nobody wants to have Mohs surgery but the fact is that you have a large forehead skin cancer that needs to be removed. If you've found an experienced fellowship trained Mohs surgeon you are in great hands. I hope this information is helpful for you.
Stephen Weber MD, FACS
Denver Facial Plastic Surgeon
Mohs surgery is considered the best way to treat skin cancers on the face because it has the highest cure rate and spares as much normal skin as possible so it gives a better cosmetic outcome. Just because the area looks like scar tissue does not mean the cancer is gone, sometimes it takes the appearance of a scar, a nonhealing sore or a shiny red bump. While basal cell carcinoma does not spread to other parts of the body commonly, if you do not get it treated it will continue to grow larger and larger and eat up normal surrounding tissue.
MOHs surgery has a high success rate for clearing basal cell skin cancer. The diagnosis of skin cancer can raise everyone's fear and anxiety . This is understandable . Timely diagnosis and thorough treatment has a high chance for cure. Delaying treatment only increased the chance for extension. It is very rare for basal cell cancer to spread further away into lymph nodes. When left unattended, skin cancer on the forehead can extend into nerves and bone . This can make it more difficult to clear but there are still treatment options. You are encouraged to seek care as soon as possible understanding that your disease is very treatable.