Is That New Spot Skin Cancer? When to Ask Your Dermatologist About Mohs Surgery

Nonmelanoma skin cancers like basal cell carcinoma and squamous cell carcinoma are among the most common cancers diagnosed in the United States. They’re also highly treatable when detected early, and Mohs surgery offers cure rates around 99% for these cancers.

At Vivida Dermatology in Las Vegas and Henderson, Nevada, and St. George, Utah, our board-certified dermatologists diagnose and treat skin cancer using Mohs surgery when precision removal is critical. a

Signs that skin changes need dermatologic evaluation

Not every new spot is cancer, but certain changes should prompt an appointment. Use the ABCDE method to monitor moles and spots:

• Asymmetry (one half doesn’t match the other)
• Border (irregular, jagged, or blurred edges)
• Color (uneven coloring or several different hues)
• Diameter (larger than a pencil eraser)
• Evolving (changes in appearance over time)

Spots that bleed, itch, or won’t heal also need evaluation. Basal cell carcinoma often appears as a pearly bump or a sore that heals and returns. Squamous cell carcinoma can appear as a scaly patch or a firm red nodule. 

How Mohs surgery removes skin cancer layer by layer

Mohs surgery treats skin cancer by removing tissue one thin layer at a time. After each layer is removed, we immediately examine it under a microscope to check for cancer cells. If cancer remains, another layer comes off. The process repeats until the margins are clear and no cancer cells are visible.

This technique removes all the cancer while preserving as much healthy tissue as possible. For skin cancers on the face, ears, hands, feet, or genitals — areas where tissue preservation is critical — Mohs surgery offers the highest cure rate with the least tissue removal.

Stages of Mohs surgery

Mohs surgery happens in stages, and each case takes a different amount of time depending on how many layers need to be removed. Most procedures take two to four hours, though some finish faster and others take longer.

The surgeon numbs the area with a local anesthetic, removes a thin layer of tissue containing the visible tumor, and sends you to a waiting area while the tissue gets processed and examined under a microscope. If cancer cells are still present at the edges, the surgeon removes another layer from only the area where cancer remains. This continues until the margins are clear.

Once all the cancer is gone, the surgeon closes the wound. Smaller wounds can close naturally without stitches. Larger wounds might need stitches or, in some cases, a skin graft or flap to close the area and minimize scarring.

Recovery after Mohs surgery

Swelling and redness around the surgical site are normal and improve over the first few days. Most people return to regular activities within a few days, though strenuous exercise and heavy lifting should wait at least a week.

Keeping the wound clean and applying prescribed ointments as directed helps it heal properly. Follow-up appointments monitor healing and check for any signs of recurrence, which is rare but possible.

When Mohs surgery is recommended

Not every skin cancer requires Mohs surgery. Standard excision works well for many cases. Mohs surgery is the preferred option for:

• Cancer on the face, ears, hands, feet, or genitals
• Poorly defined borders
• Large or aggressive tumors
• Recurrent cancers after previous treatment
• Cases where preserving healthy tissue is critical for function or appearance

Your dermatologist will recommend Mohs surgery when it offers the best combination of high cure rates and tissue preservation for your specific case.

Schedule a skin cancer evaluation

If a skin lesion or mark looks different, has changed, or won’t heal, get it checked. Catching skin cancer early makes treatment more straightforward and improves results.

Call Vivida Dermatology in Las Vegas, Henderson, Nevada, or St. George, Utah, or schedule an appointment online for a skin cancer evaluation.