For general education, not medical advice. This guide can’t diagnose you or replace care from your own clinician. If you’re worried about a spot or symptom, see a board-certified dermatologist.
Melanoma in situ is the earliest form of melanoma. It is also called Stage 0. The cells stay in the top layer of skin, called the epidermis. While they stay there, they cannot spread to other organs. Treatment removes them before they can grow deeper.
Key points
- Stage 0 means the melanoma has not grown into deeper skin.
- Complete removal offers an excellent chance of cure. Surgery is the usual treatment.1
- Keep having skin checks after treatment. Having one melanoma raises the risk of another.
What is melanoma in situ?
Melanoma starts in the cells that make skin pigment. In situ means these cells are still in the skin's top layer. Some untreated spots can grow deeper and become invasive melanoma. Prompt treatment helps prevent this.
Lentigo maligna is a type of melanoma in situ. It often grows on sun-damaged skin, such as the face. Its edges can be hard to see. Other types can also extend past their visible edges.2
Signs to watch for
Look for a new or changing flat spot. It may be brown, black, pink, or have more than one color. Watch for an uneven shape or edge, or a spot that looks unlike your others. Small spots can be melanoma too. A spot does not have to hurt or bleed to need a check.
How it's diagnosed
Your dermatologist checks the spot, often with a dermoscope. This tool gives a close-up view of the skin. A skin biopsy is needed to confirm the diagnosis.
A pathologist checks the tissue under a microscope. They look for melanoma cells and see how deep they go. A biopsy samples tissue. If the later surgery finds deeper melanoma, the stage and treatment plan may change.
What treatment usually looks like
The goal is to remove all the melanoma. Most spots are treated with wide local excision. Your doctor removes the spot and a rim of skin around it. This is often done in the office after the skin is numbed. The tissue is sent to a lab to check the edges.1
Some spots need surgery that checks the edges in stages. This can help when the edges are hard to see or the site needs care, such as the face. Staged excision and Mohs surgery check margins in different ways. Your doctor can explain which method suits your spot.1
Read all source findings
Wide local excision
Akhtar S, Bhat W, Magdum A, Stanley PRW. J Plast Reconstr Aesthet Surg. 2014;67(3):320–323.
A retrospective study of 192 MIS lesions found two recurrences after complete excision (1.1%). Both were lentigo maligna (LM), with 2.9% recurrence in that subgroup. Incomplete excision was more common with LM. These results are not a universal recurrence rate.
Kunishige JH, Brodland DG, Zitelli JA. J Am Acad Dermatol. 2012;66(3):438–444.
In a referral-center series of 1,120 MIS lesions treated with Mohs surgery, 6 mm cleared 86% and 9 mm cleared 98.9%; three recurred (0.3%). Margins below 6 mm were not studied, and 10% had prior treatment. These are Mohs data, not direct wide-excision results.
Kunishige JH, Doan L, Brodland DG, Zitelli JA. J Am Acad Dermatol. 2019;81(1):204–212.
In 1,506 LM and 829 other MIS lesions, 97% clearance required 12 mm on the head and neck and 9 mm on the trunk and limbs. At 6 mm, clearance was 79% for LM and 83% for other MIS (P=.12). Recurrence was 0.26% at mean 5.7 years. Margins below 6 mm were not studied; spread beyond visible edges was similar between subtypes.
Nosrati A, Berliner JG, Goel S, et al. JAMA Dermatol. 2017;153(5):436–441.
A nonrandomized cohort of 662 MIS patients found five-year recurrence of 1.1% after Mohs and 4.1% after wide excision (P=.07). Survival differences were not significant. The groups differed in site and age. No clear difference was found, but equal outcomes were not proved.
Swetter SM, Tsao H, Bichakjian CK, et al. J Am Acad Dermatol. 2019;80(1):208–250.
The AAD guideline recommends wide excision with 0.5 to 1 cm margins for MIS. LM may need more. Mohs or staged excision can help assess margins on constrained sites. The goal is clear tissue edges.
Margin-controlled (staged) excision
Felton S, Taylor RS, Srivastava D. Dermatol Surg. 2016;42(3):327–334.
In 343 head and neck MIS cases treated with Mohs, 5 mm cleared 65% and 15 mm cleared 97%. This is evidence about hidden spread and the need to check margins, not a direct study of permanent-section staged excision.
Beveridge J, Taher M, Zhu J, Mahmood MN, Salopek TG. J Surg Oncol. 2018;118(1):144–149.
A small retrospective series of 24 mostly facial LM lesions reported complete clearance with staged margin-controlled excision. It needed a mean of two procedures and a mean 9 mm margin. Median follow-up was 18 months (range 1 to 63 months), limiting long-term conclusions.
Moyer JS, Rudy S, Boonstra PS, et al. JAMA Dermatol. 2017;153(3):282–288.
In 806 patients with head and neck melanoma, including in-situ and invasive disease, staged excision with permanent sections had estimated recurrence of 1.4% at 5 years, 1.8% at 7.5 years, and 2.2% at 10 years. These are mixed-stage rates. In the MIS subgroup, margins were clear at 5 mm or less in 41.1% and at 10 mm or less in 74.5%.
Nosrati A, Berliner JG, Goel S, et al. JAMA Dermatol. 2017;153(5):436–441.
This comparison studied Mohs, not permanent-section staged excision. Five-year recurrence was 1.1% after Mohs and 4.1% after wide excision (P=.07). It found no clear recurrence or survival difference; its nonrandomized design does not prove equal outcomes.
Clark GS, Pappas-Politis EC, Cherpelis BS, et al. Cancer Control. 2008;15(3):216–224.
This review discusses LM on sun-damaged skin. Permanent-section staged methods had low recurrence with only short-term data. The often quoted less-than-1% recurrence over 3 to 5 years refers to Mohs studies, not a pooled staged-excision estimate.
The choice depends on the spot's size, site, edges, and your health. Stage 0 disease does not need chemotherapy or drugs that treat the whole body. Skin checks remain part of care after removal.
Margins: why extra skin is removed
The rim of skin taken with the spot is called the margin. A clear margin means no melanoma cells were found at the cut edge. A clear-looking border on the skin is not the same as a clear margin in the lab.
A small rim may not remove all the cells. In one study of 1,120 spots treated with Mohs surgery, a 6 mm margin cleared 86%. A 9 mm margin cleared 98.9%. The study did not test margins smaller than 6 mm. These results do not set the right margin for every person.3
Your doctor chooses the margin and checks the lab result. If cells reach the edge, you may need more skin removed.
Other options patients ask about
Cream or radiation: a limited role for lentigo maligna. If surgery cannot be done, a specialist may consider imiquimod cream or radiation for the lentigo maligna type. These are not routine replacements for surgery for all melanoma in situ. They need close follow-up and may leave cancer behind. See the lentigo maligna guide for the evidence and limits.1
Freezing, laser, and other creams: not a home treatment plan. Treatments used for other skin problems are not proven substitutes for complete removal of melanoma in situ. Destroying the surface does not show whether deeper cells or cancer at the edges remain.4
Black salve and home removal: can harm. Do not burn, cut, or scrape off the spot yourself. Black salve can destroy healthy skin and leave cancer behind. A scar does not prove the cancer is gone.5
Vitamins and natural remedies: no proven cure. No complementary approach has been shown to cure cancer. Supplements, oils, and diets should not replace or delay treatment.5
Watchful waiting: discuss the risks with your doctor. Leaving a spot untreated is not the usual plan. Some can grow deeper. Serious illness or frailty may change the balance of treatment and harm. For selected people with lentigo maligna, a specialist may discuss planned monitoring. This needs follow-up; it is not the same as ignoring a changing spot.6
Do I need scans or a lymph node test?
Not for confirmed Stage 0 melanoma alone. It has not reached the skin layers through which it could spread. Routine body scans and a sentinel lymph node biopsy are not needed for in-situ disease. If deeper melanoma is found, your doctor will check whether other tests are needed.1
Reducing your risk going forward
Protect your skin from the sun and avoid tanning beds. Check your skin as your dermatologist advises. Keep regular skin checks, even after the spot heals. For some people with many moles, total body photography can help track changes.
When to see a doctor
Have a new, changing, or unusual spot checked promptly. After treatment, call if pigment returns near the scar or you notice a new lump or change. Keep your planned skin checks even when you feel well.
Worried about a spot?
SpotDoc offers full-body skin cancer screening in Brownwood Square, The Villages. No referral needed for most plans.
Frequently asked questions
Is melanoma in situ dangerous? It cannot spread to other organs while it stays in situ. Some untreated spots can grow deeper. That is why it needs prompt care, even though the outlook with complete removal is excellent.
Will I need anything besides surgery? Usually, removal and skin follow-up are enough for Stage 0 disease. If the tissue shows deeper melanoma, the treatment plan may change.
How is this different from lentigo maligna? Lentigo maligna is one type of melanoma in situ. It often occurs on sun-damaged skin and can have hard-to-see edges. Other types can also extend beyond what the eye can see.
Can it come back after removal? Yes, though the risk is low after complete removal. It varies with the spot, the treatment, and the length of follow-up. A small study found two recurrences after complete excision; both were lentigo maligna. One number cannot predict everyone's risk.7
How big will the scar be? The wound will be larger than the spot because of the margin. Some wounds close in a line. Larger wounds or certain sites may need a skin flap or graft. Ask about the likely repair before surgery.
How often should I get my skin checked afterward? AAD guidance suggests a skin exam at least every 6 to 12 months for the first 1 to 2 years, then at least once a year. Your doctor may advise more frequent checks based on your skin and history.1
Questions to ask your dermatologist
- Is the melanoma only in situ, or was any deeper disease found?
- Were the margins clear, or do I need more skin removed?
- Which surgery and wound repair do you recommend, and why?
- How often should I have skin checks?
- What changes should make me call sooner?
Reviewed by Tyler Long, DO. Last reviewed November 3, 2026.
Update log
How this guide has changed since it was first published.
- November 3, 2026Corrected surgical-study scope and margin descriptions, clarified follow-up, and added safety information. Reviewed and accepted for publication November 3, 2026.
- August 18, 2026Guide published.
References
Sources supporting this guide are listed below, with links to the publications or issuing organizations. Numbers match the citations in the text and the grids above.
- Swetter SM, Tsao H, Bichakjian CK, et al. Guidelines of care for the management of primary cutaneous melanoma. J Am Acad Dermatol. 2019;80(1):208–250.View source
- Kunishige JH, Doan L, Brodland DG, Zitelli JA. Comparison of surgical margins for lentigo maligna versus melanoma in situ. J Am Acad Dermatol. 2019;81(1):204–212.View source
- Kunishige JH, Brodland DG, Zitelli JA. Surgical margins for melanoma in situ. J Am Acad Dermatol. 2012;66(3):438–444.View source
- Tzellos T, Kyrgidis A, Mocellin S, Chan AW, Pilati P, Apalla Z. Interventions for melanoma in situ, including lentigo maligna. Cochrane Database Syst Rev. 2014;(12):CD010308.View source
- National Center for Complementary and Integrative Health. Cancer and Complementary Health Approaches: What You Need To Know. National Institutes of Health. Accessed November 3, 2026.View source
- Forsea AM, Pampena R, Akay BN, et al. International Dermoscopy Society consensus recommendations for the management of lentigo maligna. J Eur Acad Dermatol Venereol. 2026;40(10):1600–1617.View source
- Akhtar S, Bhat W, Magdum A, Stanley PRW. Surgical excision margins for melanoma in situ. J Plast Reconstr Aesthet Surg. 2014;67(3):320–323.View source
- Nosrati A, Berliner JG, Goel S, et al. Outcomes of melanoma in situ treated with Mohs micrographic surgery compared with wide local excision. JAMA Dermatol. 2017;153(5):436–441.View source
- Felton S, Taylor RS, Srivastava D. Excision margins for melanoma in situ on the head and neck. Dermatol Surg. 2016;42(3):327–334.View source
- Beveridge J, Taher M, Zhu J, Mahmood MN, Salopek TG. Staged margin-controlled excision (SMEX) for lentigo maligna melanoma in situ. J Surg Oncol. 2018;118(1):144–149.View source
- Moyer JS, Rudy S, Boonstra PS, et al. Efficacy of staged excision with permanent section margin control for cutaneous head and neck melanoma. JAMA Dermatol. 2017;153(3):282–288.View source
- Clark GS, Pappas-Politis EC, Cherpelis BS, et al. Surgical management of melanoma in situ on chronically sun-damaged skin. Cancer Control. 2008;15(3):216–224.View source