Mohs Micrographic Surgery – Indications, Procedure, Risk

Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

On this page6 sections

Article Summary

Mohs surgery is a way to treat and cure certain skin cancers. Surgeons trained in the Mohs procedure can do this surgery. It allows skin cancer to be removed with less damage to the healthy skin around it. Description Mohs surgery usually takes place in the doctor's office. The surgery is started early in the morning and is done in one day. Sometimes if the...

Key Takeaways

  • This article explains Description in simple medical language.
  • This article explains Why the Procedure is Performed in simple medical language.
  • This article explains Risks in simple medical language.
  • This article explains Before the Procedure in simple medical language.
Before reading

RX Patient Tools

Use these quick guides before reading the article, or return to them when you need help preparing questions for a doctor.

Start here Choose the right pathway for symptoms, reports, medicines, or urgent warning signs. Disease article roadmap Read this topic step by step: meaning, symptoms, warning signs, diagnosis, treatment, prevention, and follow-up. Treatment planner Prepare questions about treatment choices, benefits, risks, side effects, and follow-up. Family & caregiver guide Organize symptoms, reports, medicines, questions, and follow-up safely. Nutrition & diet guide Prepare food, hydration, supplement, and medicine-timing questions safely. Prevention guide Organize risk factors, protective habits, screening, and warning signs. Recovery guide Prepare a safe plan for activity, rehabilitation, warning signs, and follow-up.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.
Choose your reading view

Patient View highlights a simple learning journey. Clinical View reveals structure, evidence, and editorial completeness.

Definition

Mohs surgery is a way to treat and cure certain skin cancers. Surgeons trained in the Mohs procedure can do this surgery. It allows skin cancer to be removed with less damage to the healthy skin around it.

Description

Mohs surgery usually takes place in the doctor’s office. The surgery is started early in the morning and is done in one day. Sometimes if the is big or you need reconstruction, it could take 2 visits.

During the procedure, the Mohs surgeon removes the cancer one layer of skin at a time until all the cancer has been removed. The surgeon will:

  • Numb your skin where cancer is so you do not feel any . You stay awake for the procedure.
  • Remove the visible tumor along with a thin layer of tissue next to the tumor.
  • Look at the tissue under a microscope.
  • Check for cancer. If there is still cancer in that layer, the doctor will take out another layer and look at that under the microscope.
  • Keep repeating this procedure until there is no cancer found in a layer. Each round takes about 1 hour. The surgery takes 20 to 30 minutes and looking at the layer under the microscope takes 30 minutes.
  • Do about 2 to 3 rounds to get all of the cancer.
  • Stop any bleeding by applying a pressure dressing, using a small probe to heat the skin (electrocautery), or giving you a stitch.

Why the Procedure is Performed

Mohs surgery can be used for most skin cancers, such as basal cell or squamous cell skin cancers. For many skin cancers, other simpler procedures can be used.

Mohs surgery may be preferred when the skin cancer is on an area where:

  • It is important to remove as little tissue as possible, such as the eyelids, nose, ears, lips, or hands
  • Your doctor needs to be certain the entire tumor is removed before stitching you up
  • There is a scar or prior radiation treatment was used
  • There is a higher chance the tumor will come back, such as on the ears, lip, nose, eyelids, or temples

Mohs surgery may also be preferred when:

  • The skin cancer was already treated, and it was not completely removed or it came back
  • The skin cancer is large, or the edges of the skin cancer are not clear
  • Your immune system is not working well due to cancer, cancer treatments, or medicines you are taking

Risks

Mohs surgery is generally safe. With Mohs surgery, you do not need to be put asleep (general anesthesia) as you would with other surgeries.

While rare, these are some risks for this surgery:

  • Nerve damage that causes or a burning sensation. This usually goes away.
  • Larger scars that are raised and red, called keloids
  • Bleeding

Before the Procedure

Your doctor will explain what you should do to prepare for your surgery. You may be asked to:

  • Stop taking certain medicines, such as aspirin or other blood thinners. DO NOT stop taking any medicines unless your doctor tells you to stop.
  • Stop smoking
  • Arrange to have someone take you home after your surgery

After the Procedure

Taking proper care of your wound after surgery will help your skin look its best. Your doctor will talk with you about your options:

  • Let a small wound heal itself. Most small wounds heal well on their own.
  • Use stitches to close the wound.
  • Use skin grafts. The doctor covers the wound using skin from another part of your body.
  • Use skin flaps. The doctor covers the wound with the skin next to your wound. Skin near your wound matches in color and texture.

Outlook ()

Mohs surgery has a 99% cure rate in treating skin cancer.

With this surgery, the smallest amount of tissue possible is removed. You will have a smaller scar than you might have with other treatment options.

 

National Cancer Institute: PDQ Skin Cancer Treatment. Bethesda, MD: National Cancer Institute. Date last modified July 20, 2012. Available at: www.cancer.gov/cancertopics/pdq/treatment/skin/HealthProfessional . Accessed August 19, 2013.

Upjohn E, Taylor RS. Mohs surgery. Rigel: Cancer of the Skin . 2nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 47.

RX Medical Knowledge Graph

Explore this medical topic

Continue through verified related conditions, investigations, medicines, and patient guides. These links are educational and do not replace professional medical advice.

RX Clinical Pathway Engine

Continue through a complete learning pathway

Move from understanding the topic to symptoms, tests, treatment, medicines, monitoring, and prevention.

Search the complete library
  1. Understand the condition Begin with the essential facts and a clear explanation of the topic.
  2. Recognize symptoms Learn common symptoms, signs, and patterns of presentation.
  3. Know when to seek help Review urgent warning signs and when professional assessment may be needed.
  4. Understand causes and risks Explore causes, risk factors, mechanisms, and contributing conditions.
  5. Explore tests and diagnosis Learn how clinicians assess the condition and which investigations may be discussed.
  6. Learn treatment approaches Review general treatment categories and management principles.
  7. Understand medicines safely Continue to medicine education, uses, precautions, and monitoring.
  8. Plan monitoring and follow-up Understand monitoring, complications, rehabilitation, and follow-up learning.
  9. Review prevention and self-care Explore prevention, healthy routines, and questions to discuss with a clinician.

Conditions & Diseases

Background, symptoms, causes, diagnosis, and care.

Explore this library

Tests & Investigations

Laboratory, imaging, screening, and diagnostic education.

Explore this library

Medicines

Uses, safety, monitoring, and related medicine knowledge.

Explore this library
Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Mohs Micrographic Surgery – Indications, Procedure, Risk

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.