But there’s an even bigger reason you should visit an expert. After dermatologists remove a growth, they’ll look at it under a microscope. “There are things that look like skin tags but are cancerous,” says Dr. Rossi. That doesn’t mean you should freak out if you do find a skin tag. Most will just be benign, but you won’t know for sure until you’ve asked. Plus, checking a skin tag is a “good excuse” to get your doctor to check the rest of your body for skin cancer and atypical or malignant growths, says Dr. Rossi. Next, read up on these things you should never, ever do to your skin.