When you have skin cancer, cells in your skin begin growing abnormally and forming visible changes on your body’s surface. What happens next depends heavily on the type of skin cancer involved, but the general arc is the same: you notice something unusual on your skin, a doctor takes a small sample to confirm the diagnosis, and treatment follows. Most skin cancers are highly treatable when caught early, with cure rates reaching up to 99% for certain procedures. The experience varies widely, though, from a minor office procedure to a longer course of treatment for cancers that have grown deeper.
How Skin Cancer Starts
Skin cancer begins when ultraviolet radiation from the sun or tanning beds damages the DNA inside your skin cells. Normally, your body has a built-in repair system that finds these errors and fixes them. But when that repair system is overwhelmed or has its own defects, damaged cells can start multiplying without the usual checks in place. Those rapidly dividing cells form a growth that can invade and destroy the healthy tissue around it.
This process doesn’t happen overnight. UV exposure causes cumulative damage over years or decades, which is why skin cancer becomes more common as people age. The specific type of skin cancer you develop depends on which cells are affected: the flat cells near the skin’s surface (squamous cells), the round cells beneath them (basal cells), or the pigment-producing cells (melanocytes).
What Each Type Looks and Feels Like
Basal Cell Carcinoma
Basal cell carcinoma is the most common form. It often looks like a slightly transparent or pearly bump on the skin. On lighter skin, the bump tends to be skin-colored or pink. On darker skin, it typically appears brown or glossy black with a rolled border. You might notice tiny blood vessels on the surface, and the bump may bleed, scab over, and then seem to heal before bleeding again. Some basal cell carcinomas look quite different: a flat, scaly patch, or a white, waxy, scar-like area without a clear edge. They grow slowly and rarely spread to other parts of the body, but left alone, they can destroy surrounding tissue and grow into bone or nerves.
Squamous Cell Carcinoma
Squamous cell carcinoma often appears as a firm bump or nodule that can be pink, red, brown, or black depending on your skin tone. It may also show up as a flat sore with a scaly crust, a rough patch on the lip, or a new raised area on an old scar. Unlike basal cell carcinoma, untreated squamous cell carcinoma can spread to lymph nodes and other organs. The risk of spreading is higher when the cancer grows very large or deep, involves mucous membranes like the lips, or develops in someone with a weakened immune system.
Melanoma
Melanoma is less common but far more dangerous. It usually appears as a new or changing mole. Doctors use the ABCDE checklist to evaluate suspicious spots: Asymmetry (one half doesn’t match the other), Border irregularity, Color variation within the same mole, Diameter larger than a pencil eraser, and Evolving size, shape, or color. The thickness of a melanoma, measured in millimeters from the surface down to the deepest point of tumor growth, is the single most important factor in determining how serious it is. Thicker tumors correlate strongly with a higher chance of spreading.
How Diagnosis Works
If your doctor suspects skin cancer, the next step is a biopsy, a quick in-office procedure where a small sample of the suspicious area is removed and examined under a microscope. There are a few methods. A shave biopsy removes only a thin surface layer and doesn’t require stitches. A punch biopsy uses a small circular tool to take a deeper core of tissue. An excisional biopsy uses a scalpel to remove a larger sample. Your doctor chooses the method based on the size and location of the spot. The procedure is done under local anesthesia, and results typically come back within a week or two.
If the biopsy confirms cancer, doctors stage it using a system based on three factors: the size and depth of the tumor, whether cancer has reached nearby lymph nodes, and whether it has spread to distant parts of the body. Higher numbers at each stage mean more advanced disease.
What Treatment Looks Like
For the majority of skin cancers caught early, treatment is surgical and relatively straightforward. The most precise option is Mohs surgery, where a surgeon removes the cancer one thin layer at a time. After each layer is taken, the tissue is mapped, processed, and examined under a microscope right there in the office. If cancer cells remain at any edge, the surgeon goes back and removes another layer from that exact spot, repeating until the margins are completely clear. This approach achieves cure rates up to 99% for primary basal and squamous cell carcinomas, and around 98% even in high-risk areas like the face. Because only cancerous tissue is removed, it preserves as much healthy skin as possible.
Standard excision, where the cancer is cut out along with a margin of normal-looking skin around it, is another common approach. Cure rates are slightly lower (around 93 to 95%) but still very good for most skin cancers. Other options for superficial or small cancers include freezing the growth, scraping it away, or applying topical treatments.
Advanced melanoma or skin cancers that have spread require more intensive treatment. Immunotherapy drugs that help your immune system recognize and attack cancer cells have transformed outcomes for advanced melanoma over the past decade. Targeted therapies that block specific genetic mutations driving tumor growth are another option, particularly for melanomas with certain DNA changes. These treatments are given as infusions or pills and can come with significant side effects, but they’ve dramatically improved survival for cancers that were once considered untreatable.
What Happens If It Spreads
Melanoma cells can travel from the original tumor through the lymphatic system and bloodstream. They tend to spread first to nearby lymph nodes, which act as a stopover rather than a final destination. From there, cells can enter the blood and reach distant organs and tissues. Basal cell carcinoma almost never reaches this point. Squamous cell carcinoma spreads uncommonly but can be fatal in rare cases when it does.
The survival statistics for melanoma illustrate how dramatically stage at diagnosis affects outcomes. When melanoma is still localized (confined to the skin where it started), the five-year survival rate is 97.6%. Once it reaches regional lymph nodes, that drops to 60.3%. For melanoma that has spread to distant parts of the body, the five-year survival rate falls to 16.2%. The encouraging news: about 83% of melanomas are diagnosed at the localized stage, when the odds are overwhelmingly in the patient’s favor.
Recovery and Long-Term Monitoring
After surgical treatment, healing depends on the size and location of the wound. Small shave or punch biopsy sites may heal in a couple of weeks. Larger excisions or Mohs surgery sites can take longer, and a full year isn’t unusual for scar tissue to flatten and fade completely. Your surgical team will give you wound care instructions and a schedule for follow-up appointments to remove stitches and check healing.
The follow-up schedule after skin cancer extends well beyond wound healing. Once you’ve had one skin cancer, your risk of developing another is significantly higher than someone who’s never had one. Post-treatment checkups may continue for many years, with your doctor examining your skin for new or recurring growths. Most people settle into a routine of skin checks every few months in the first year or two, then annually or semi-annually after that. You’ll also be asked to do regular self-exams at home, looking for any new spots, changes in existing moles, or sores that won’t heal.