I know I’ve talked about skin cancer before, but previous blogs covered mostly preventative terms. Today I would like to explain some of the ways we treat it. Doctors love their medical terms (and I’m no exception), but throwing out words like “Mohs”, “shave biopsy” and “punch biopsy” right after telling someone they might have skin cancer is more than a little confusing. A little time here may save you from running to the dictionary next time you see your dermatologist or plastic surgeon.
Lets talk biopsies first. A biopsy is a way to take a sample of a suspicious spot, or lesion. We send the biopsy to the pathologist, who tells us if its cancer or not. There are a couple ways to do this:
- Shave it– using what is basically a razor blade to shave off the suspicious spot can often remove the entire area. This is aptly called a shave biopsy. These biopsy sites are usually covered with a Band-aid, and left to heal on their own. This type of biopsy works very well, but sometimes you need to know how thick the spot is (particularly if you are worried it may be melanoma). In that case you do what is called a…
- Punch biopsy – this uses what basically looks like a tiny cookie cutter to remove a small piece of skin all the way through (full-thickness). Sometimes I’ll put a stitch in these to close them, sometimes I let them heal in on their own. The benefit of a punch biopsy, as I said above, is that it lets the pathologist see the whole thickness of the skin, which is important for melanoma.
So now we’ve sent the tissue to the pathologist, and he tells us it’s a skin cancer. There are a couple different ways to treat it.
- Wide local excision. This means that the surgeon (me) takes off the skin cancer, with a margin of normal tissue. Often I will send this to the pathologist for what is called afrozen section, meaning he or she will freeze that bit of tissue and look at it to make sure I got all the cancer. This doesn’t work well for melanoma, and still isn’t 100% accurate for other types of skin cancer. We only know for sure after the pathologist processes the tissue with chemicals and special stains, which takes a few days.
- Mohs surgery. This is named after the doctor who created it, and is only done by specially-trained Mohs surgeons, who are dermatologists. This type of surgery is done in an office, using numbing medicine. The difference between this and a wide local excision, is that the Mohs surgeon first takes out the cancer, then takes out just the rim of the wound and looks at that flat under a microscope himself (as opposed to sending it to a pathologist). This concept is a little hard to explain, so check it out here. The take-home point is that Mohs surgery takes a little longer, because the surgeon takes the cancer out in multiple steps. But they remove as little normal tissue as possible, because they look at it under the microscope at each stage, and when you’re done with the Mohs surgery you know your cancer is gone.
So why use one surgery or another? On the face, which is high-value real estate, I often refer patients to a Mohs surgeon unless the skin cancer is very small. Then either he or I will close the resulting wound. On other parts of the body, where the size of the scar isn’t as important, I will often take of the cancer myself, with just a little bit more tissue to make sure we got it all. And of course I always discuss the options with the patient and let him or her decide.
Do you have any questions about types of treatment for skin cancer?