A board-certified dermatologist is specially trained to be an expert in the health of skin, hair, and nails. Dermatology is the only field of medicine with this specialty. Dermatologists are the doctors who diagnose skin cancer as part of their training and specialization. In many cases, a dermatologist can tell just by looking if a growth is skin cancer. They can also often tell just by looking if a growth is *not* skin cancer. In some in between cases, the dermatologist may recommend a small painless test called a skin biopsy to have the tissue checked under the microscope in a lab. In other cases, a dermatologist may recommend watching the spot for changes and rechecking it at a future visit in a few days, weeks, or months. In these cases it is important to keep the follow up appointment. Additionally, in some cases the growth may appear at first benign to the dermatologist, but if you know it is new, unusual, or bothersome in a unique way, it may be worth asking for the biopsy anyway. On rare occasion, growths that appear benign at first can turn out to need more treatment.