13312 Mohs Surgery

Overview

Mohs surgery (also called Mohs micrographic surgery) is a very precise way to remove certain skin cancers. The doctor removes a thin layer of skin and checks it under a microscope straight away. If cancer cells are still seen at the edge, another thin layer is taken from that exact spot. This keeps going until the edges are clear. Because each layer is checked during the operation, Mohs removes the cancer while saving as much healthy skin as possible. It is usually done in one visit with numbing medicine to the area, and you stay awake.

Yes. Mohs surgery is one of the most common and trusted treatments for the two most common types of skin cancer (basal cell and squamous cell carcinoma). Thousands of people have it every year, mostly on the face and head.

It is most often used in adults, especially people with fair skin and a history of sun exposure, sunbed use, or previous skin cancers. It becomes more common with age because sun damage builds up over a lifetime. It can be used in younger adults too, and in rare cases in children, usually with extra planning and specialist care.

Symptoms

Common symptoms

• A sore or spot that does not heal within a few weeks, or heals and then comes back
• A pearly or shiny bump, sometimes with tiny visible blood vessels
• A red, scaly, or crusty patch that may itch or bleed
• A small wound or scab that bleeds easily when touched
• A new or changing lump, spot, or mole, including changes in shape, colour, or size
• A flat, firm, scar-like area that feels different from the skin around it

Symptoms in children

• Skin cancer is rare in children, so these signs are much more likely to have another cause
• A new or changing spot, lump, or sore that does not heal should still be checked by a doctor
• Children with rare inherited conditions or a weakened immune system may have a higher risk
• If a child needs Mohs surgery, it is usually done by a specialist team and may need a general anaesthetic

Symptoms in older adults

• Skin cancers are more common with age because sun damage adds up over the years
• Older skin may be thinner and heal more slowly, so wound care plans are tailored
• Blood-thinning medicines may need to be discussed with your doctor before surgery
• Bring a list of all your medicines and arrange a ride home if you may feel tired afterwards

Causes

Main causes

• Mohs surgery treats skin cancers, most often basal cell and squamous cell carcinoma
• These cancers are mostly caused by damage to skin cells from ultraviolet (UV) light in sunshine and sunbeds
• UV damage builds up over years, so cancers often appear on skin that has had a lot of sun
• Some skin cancers are linked to other factors, such as certain medicines that weaken the immune system, long-term scars, or rare inherited conditions

Risk factors

• Fair skin, light eyes, or hair that burns easily in the sun
• A lot of sun exposure over your life, or a history of sunburn
• Using sunbeds or tanning lamps
• Previous skin cancers or pre-cancerous skin patches
• A weakened immune system, for example after an organ transplant or from some medicines
• Older age, because sun damage collects over time
• A family history of skin cancer
• Rare inherited conditions that make the skin or eyes very sensitive to sunlight

When to see a doctor

See a doctor urgently if:

• A spot, lump, or sore that is bleeding a lot or will not stop bleeding
• A new lump that is growing quickly over days or weeks
• A wound or sore that is spreading, very painful, or looks infected
• A mole or spot that has changed suddenly in shape, colour, or size
• Any of the emergency or urgent wound signs listed above after surgery

Book a routine appointment if:

• A sore or spot that has not healed after 4 weeks
• A bump or patch that itches, crusts, bleeds, or changes over time
• A new spot on sun-exposed skin, especially on the face, ears, neck, or hands
• A history of skin cancer and you notice something new
• You have questions about an upcoming Mohs appointment or your wound care

Diagnosis

The process usually starts with a skin examination. Your doctor will look closely at the area, sometimes using a handheld magnifier with a light (a dermatoscope) that shows skin layers more clearly. If the spot looks suspicious, a small sample (a biopsy) is taken and checked in a laboratory. Only after cancer is confirmed by that test would Mohs surgery be planned. During Mohs, the removed skin is checked under the microscope straight away, which helps confirm the cancer is fully removed.

Tests that may be done

• Skin examination with a dermatoscope (a lighted magnifying tool)
• Skin biopsy: a small sample of the spot is sent to a laboratory
• Laboratory examination of each thin layer removed during Mohs surgery
• Photographs of the area to plan and record the surgery
• Blood tests or other checks only if needed for your general health or medicines
• Imaging scans are rarely needed, for example if a cancer is large or deep

What to expect at your appointment

Before the day, you will have a consultation where the doctor explains the plan, the risks, and the choices. On the day, the area is cleaned and numbed with an injection. A thin layer of skin is removed and you wait while it is checked. This may repeat a few times, so plan to be there most of the day and bring something to read, snacks, and a friend or family member if you like. Most people feel pressure rather than pain during the numbing and cutting, and the area is numb throughout.

Treatment

Mohs surgery is one of several ways to treat skin cancer. The aim is to remove the cancer completely while keeping as much healthy skin as possible. Your doctor will recommend the option that best fits the type, size, and place of your cancer, your age, and your general health. Other options include simply cutting the cancer out and testing the edges afterwards, freezing, scraping and burning, radiation therapy, light-based therapy, or creams that treat the skin's surface. Small or very early cancers may not need Mohs at all.

Self-care at home

• Follow your wound care instructions exactly; keep the area clean and dry as advised
• Change dressings as your care team told you, and wash your hands before touching the wound
• Ask your pharmacist which pain relief is safe for you, and follow the label
• Keep the area out of direct sun and use a high-factor sunscreen on healed skin
• Do not pick at scabs or stitches; ask when stitches should be removed
• Avoid heavy lifting, stretching, or sports for as long as your care team advises
• Keep your follow-up appointments, and check your skin monthly for new or changing spots

Medical treatments

Mohs surgery itself is the treatment. Alongside it, your care team may suggest other approaches depending on your situation: other types of surgery, radiation therapy (high-energy rays that destroy cancer cells), light therapy, or creams applied to the skin that treat early surface cancers. For cancers that are large or have spread, specialist teams may use treatments that help the immune system fight cancer cells or target specific cancer features. Your doctor will explain which approach suits you and why. Always ask about the benefits, risks, and alternatives before deciding.

When is surgery considered?

Mohs is usually suggested when a skin cancer is on the face, ears, nose, eyelids, lips, hands, or other areas where saving healthy skin matters most. It is also used when a cancer is large, has come back after earlier treatment, has edges that are hard to see, or is a type that can spread. Sometimes your doctor will suggest a simpler removal instead, and that is normal. The choice is based on your cancer and your preferences.

Living with this condition

Most people recover well. The wound area may be sore, bruised, or swollen for a few days, and stitches usually come out within one to two weeks, depending on the site. Expect a scar, which will fade over months. Keep the area protected from the sun while it heals, and follow any limits on exercise or heavy lifting. Many people go back to normal activities quickly, but it is fine to rest if you feel tired.

Lifestyle tips

• Protect your skin every day: shade, clothing, a hat, sunglasses, and sunscreen on exposed skin
• Avoid sunbeds and tanning lamps completely
• Check your skin once a month, using a mirror or asking someone to help with your back and scalp
• Take photos of any spot you are watching, so you can see change over time
• Keep all skin check appointments, especially if you have had skin cancer before
• Tell your dentist or other health professionals about surgery on your face or head if relevant

Diet and exercise

No special diet is needed, but eating well and drinking enough water helps your skin heal. Gentle movement, like short walks, is usually fine soon after surgery and can help you feel better. Ask your care team when you can return to swimming, gym workouts, or heavy lifting, because wounds on some parts of the body need longer protection. Smoking slows healing, so this is a good time to get support to stop.

Mental health and emotional wellbeing

It is common to feel anxious before surgery and worried while waiting for results. Many people also feel self-conscious about a scar, especially on the face. These feelings usually settle, but if worry, low mood, or sleep problems last more than a couple of weeks, tell your doctor. You are not being a nuisance, and support is available. If you ever have thoughts of harming yourself, contact your local emergency number or a crisis line right away.

Prevention

You cannot change your skin type or past sun exposure, but you can greatly lower your risk of future skin cancers. Protect your skin from strong sun, especially in the middle of the day, and never use sunbeds. If you have had one skin cancer, you have a higher chance of another, so regular skin checks matter. Finding a new spot early means simpler treatment.

Vaccines

There is no vaccine that prevents the common skin cancers treated with Mohs surgery. Some other skin conditions have different prevention measures, so ask your doctor if you are unsure.

Screening programmes

There is no single national screening test for skin cancer in most countries. Instead, be skin-aware: check your own skin monthly and ask your doctor about any new, changing, or non-healing spot. If you have had skin cancer or are at higher risk, your doctor may suggest regular skin checks. In the UK, NHS guidance covers signs to look for and when to see a GP.

Complications

If left untreated

• The cancer can keep growing and damage nearby skin, muscle, or bone
• It can spread to other parts of the body, which is uncommon but serious
• Treatment later may be more extensive and leave a larger scar
• A wound that is left untreated can become infected or painful

Long-term outlook

The outlook is generally very good. For the skin cancers Mohs surgery is used for, cure rates are high, and most people heal well with a small scar. Mohs is designed to remove the cancer completely while saving healthy skin. As with any procedure, there are small risks such as bleeding, infection, a noticeable scar, or numbness, and rarely the cancer can come back. Keeping follow-up appointments and protecting your skin gives you the best chance of a good long-term result.

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