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Full-length video Where can I learn more about melanoma?
How common is melanoma?
How Common Is Melanoma?
Melanoma is less common than basal cell or squamous cell carcinoma, but it causes more concern because invasive melanoma can spread. Population counts show the public-health burden; they do not tell one person how their melanoma will behave.1
Cutaneous melanoma is a cancer of skin melanocytes that can begin in previously normal-looking skin or in association with a mole.
Evidence by the NumbersOne year in the United States
One year in the United States
112,000 invasive diagnoses / 8,510 deaths
- Population
- All United States residents represented by national cancer projections
- Outcome
- Projected new diagnoses of invasive melanoma of the skin and projected deaths from melanoma of the skin; these are two different annual endpoints with no matched-cohort comparator
- Time horizon
- Calendar year 2026
What it means: Melanoma is common enough to recognize and treat promptly, but these population counts do not estimate one person's chance of dying.
Limitations: The diagnosis and death counts are official projections based on earlier reported data. They do not describe the same patients and must not be divided to create a fatality rate.
References: 1
What causes melanoma, and who is at higher risk?
What Causes Melanoma, and Who Is at Higher Risk?
There is rarely one cause that can be assigned to one person. Melanoma develops through an interaction of cell biology, ultraviolet exposure, inherited susceptibility, and chance. A diagnosis is not proof that someone “caused” their cancer.3,4
Factors that can raise risk include:
- ultraviolet radiation from the sun or indoor tanning;
- skin that burns or freckles easily, although melanoma can occur in every skin tone;
- many moles or atypical moles;
- a personal history of melanoma;
- a family history of melanoma or a known inherited melanoma syndrome; and
- a weakened immune system, including some people taking immunosuppressive medicines.3,4
Risk factors describe who deserves more vigilance. They do not diagnose a spot. A person with several risk factors may never develop melanoma, while someone without an obvious risk factor can.
Evidence by the NumbersMost melanomas were not linked to a pre-existing mole
Most melanomas were not linked to a pre-existing mole
70.9% de novo / 29.1% nevus-associated
- Population
- 20,126 melanomas included in 38 observational cohort and case-control studies
- Outcome
- Pooled classification of melanoma origin as de novo in previously normal-appearing skin versus associated with a pre-existing nevus
- Time horizon
- Evidence synthesized in a 2017 meta-analysis
What it means: Watch for new spots as well as changes in existing moles; melanoma does not need a mole to begin.
Limitations: Between-study heterogeneity was very high (I-squared 99%), so the pooled percentages support recognition teaching rather than prediction of one lesion's origin or behavior.
References: 2
What can melanoma look like?
What Can Melanoma Look Like?
The ABCDE pattern is useful for noticing lesions:
- A — Asymmetry: one part does not match another.
- B — Border: the edge is irregular, scalloped, or poorly defined.
- C — Color: colors vary within the lesion.
- D — Diameter: a larger diameter can be concerning, but a melanoma can be smaller than the usual diameter cue.
- E — Evolving: the spot is new or changing in size, shape, color, surface, sensation, or behavior.5
Two additions are especially practical:
- Ugly duckling: one spot looks unlike the rest of that person’s spots.
- Not only dark: melanoma can be pink, reddish, flesh-colored, or otherwise lightly pigmented.6
Some melanomas do not meet the classic pattern. Nodular, amelanotic, acral, and nail melanomas may be missed if a person looks only for a flat, dark, irregular mole. Palms, soles, nails, scalp, and other hard-to-see areas still count as skin.
A realistic example
A person notices a small pink bump that has grown while every nearby spot has stayed stable. It is round and has one color, so it does not trigger the full ABCDE checklist. “It looks normal by ABCDE” is not a diagnosis. Its new and evolving behavior is enough reason for an in-person evaluation.
Memorable rule: Color can warn; color cannot clear.
What do melanoma stage terms mean?
What Do “In Situ,” “Invasive,” “Regional,” and “Distant” Mean?
The epidermis is the outer skin layer. Below it lies the dermis, which contains lymphatic and blood vessels. That boundary explains why in situ and invasive are not interchangeable.8–10
| Extent | Where the melanoma is | Can it metastasize in this state? | What information matters next | Patient meaning |
|---|---|---|---|---|
| Melanoma in situ (stage 0) | Confined to the epidermis in the examined tissue | A truly in-situ melanoma has not invaded the dermis and therefore is not thought to metastasize; rarely, an invasive focus may be found when more tissue is examined | Confirm the diagnosis, subtype, site, and complete local clearance | It is the earliest anatomic form. It still needs treatment because it can enlarge and may become invasive. |
| Localized invasive melanoma | Has crossed below the epidermis but no regional or distant spread is known | Yes, potential exists, but risk varies greatly | Breslow thickness, ulceration, margins, examination, and whether nodal staging is relevant | “Invasive” does not mean “metastatic.” Many invasive melanomas are found while still localized. |
| Regional melanoma | In nearby skin deposits, lymphatic pathways, or regional lymph nodes | Spread has occurred beyond the primary site but not to a distant organ in this category | Exact regional pattern, node findings, resectability, and complete stage | Regional disease changes both recurrence risk and the purpose of treatment. |
| Distant metastatic melanoma | In a distant skin site, nonregional node, or organ | Yes—distant spread is present | Sites and burden of disease, symptoms, tumor testing, health, and treatment response | Care is multidisciplinary and usually centers on systemic disease control, sometimes with local treatment for selected problems. |
A realistic example
Two reports can both say melanoma but describe very different states. One may show melanoma confined to the epidermis. Another may show an invasive tumor with measurable depth and ulceration. The diagnosis label is shared; the anatomic boundary and next decisions are not.
Memorable rule: In situ means “still on top,” not “safe to ignore.” Invasive means “crossed the boundary,” not “already metastatic.”
What does the melanoma pathology name mean?
What Does the Pathology Name Mean?
Pathology does more than attach a cancer label. It describes the features that determine the next branch. Treatment should not be discussed as if all melanomas are equivalent before these terms are understood.8–12
| Pathology term | Plain-language meaning | Decision it can affect | A useful patient question |
|---|---|---|---|
| Melanoma in situ | Melanoma cells remain in the epidermis | Local margin strategy; no sentinel-node staging for a truly in-situ tumor | “Is there any invasive component?” |
| Invasive melanoma | Melanoma cells have crossed below the epidermis | Depth-based surgery, whether nodal staging should be discussed, and complete stage | “What is the measured depth?” |
| Breslow thickness | The measured depth of the invasive melanoma under the microscope | Primary-tumor category, surgical planning, nodal-staging discussion, and prognosis | “What is my Breslow thickness, and was the deepest point captured?” |
| Ulceration | Microscopic loss of the surface over the tumor, not merely a scratch or bleeding noticed at home | Primary-tumor category and risk estimate | “Was true histologic ulceration present?” |
| Margins | Whether melanoma reaches an examined edge of the biopsy specimen | Need for additional local removal; interpretation depends on biopsy type | “Which margin is involved, and what does that change?” |
| Mitotic rate | How often melanoma cells are seen dividing | Adds prognostic or planning context but does not replace Breslow thickness or define the current T1 substage by itself | “Does this feature change any decision in my complete context?” |
| Subtype and anatomic site | The growth pattern and where it arose | Margin definition, specialist needs, and whether a site-specific pathway applies | “Does the subtype or location change how the edges should be managed?” |
| Microsatellite, satellite, in-transit disease, or node involvement | Regional melanoma deposits away from the main tumor | Regional stage and multidisciplinary planning | “Has any regional disease been found?” |
A positive biopsy margin does not by itself prove that melanoma has metastasized. It means melanoma reaches an examined specimen edge and additional local management is usually needed. Conversely, a clear biopsy edge does not by itself establish the complete stage. 10,11
Memorable rule: Depth first. Ulceration next. Extent completes the stage.
How can melanoma grow or spread if untreated?
How Can Melanoma Grow or Spread If It Is Untreated?
Melanoma does not follow one clock.
- An untreated melanoma in situ can extend within the epidermis and may eventually become invasive.
- An untreated invasive melanoma can grow deeper at the original site.
- Once invasive, melanoma may enter lymphatic or blood vessels and spread to nearby skin, regional lymph nodes, or distant organs.
- Some melanomas change slowly; others change over a shorter interval. Appearance, pain, and bleeding do not reliably reveal depth or stage.8–10
No single reliable percentage or waiting period predicts when one in-situ lesion will become invasive or when one invasive melanoma will spread. That uncertainty is a reason for prompt evaluation and treatment, not a reason for panic.
Evidence by the NumbersExtent changes group outcomes
Extent changes group outcomes
>99% localized / 76.0% regional / 34.0% distant
- Population
- People with melanoma of the skin in SEER 21 cancer registries excluding Illinois, all races and both sexes, within each broad SEER Combined Summary Stage group
- Outcome
- Five-year relative survival, comparing observed survival in each melanoma extent group with expected survival in a similar general population
- Time horizon
- Diagnoses from 2016 through 2022; outcome measured at five years
What it means: Finding melanoma before spread matters, but a useful personal prognosis still requires the complete pathology and exact stage.
Limitations: These rounded registry estimates use broad SEER summary-stage groups, not AJCC substages, and do not account for every pathology feature, treatment, health condition, or treatment response.
References: 1
Why a stage statistic is not your forecast
A registry groups many different people together. A patient’s useful prognosis begins with the complete pathology and exact stage, then considers health, tumor biology, available treatment, and response. Even a precise population percentage cannot tell an individual what will happen.
Memorable rule: A stage statistic describes a group, not a destiny.
How urgent is melanoma evaluation or treatment?
How Urgent Is Evaluation or Treatment?
Use prompt, planned, not panicked as the default.
- A new, changing, bleeding, persistently irritated, or distinctly different lesion: arrange an in-person skin evaluation promptly rather than watching indefinitely.
- A pathology report that says melanoma: contact the clinician managing the result, make sure the complete report is available, and ask what must be clarified before definitive treatment.
- A report with uncertain depth, an unusual diagnosis, or a major treatment consequence: ask whether dermatopathology review is appropriate.
- New neurologic symptoms, breathing difficulty, severe uncontrolled pain, or other acute illness in a person with known melanoma: seek urgent medical assessment based on the symptom, not on the article.
Most newly diagnosed skin melanomas do not require an emergency-department visit solely because the report arrived. They do require an organized plan. Do not postpone care on your own because the spot is painless, because the biopsy removed what was visible, or because the word in situ sounds harmless.
How is melanoma diagnosed and staged?
How Is Melanoma Diagnosed and Staged?
1. Clinical evaluation
A clinician reviews the lesion’s history, examines the skin, and may use a dermatoscope for magnified surface patterns. This determines whether a biopsy is needed; it does not create the final diagnosis.7,8
2. Skin biopsy
Tissue is removed so a pathologist can examine the cells. The biopsy should be planned to preserve the information needed to diagnose melanoma and measure invasion. Sometimes the first specimen does not capture the deepest point or leaves an important question unresolved; the clinician and pathologist then decide what additional tissue or review is needed.7,8,10,11
3. Pathology review
The report identifies melanoma in situ versus invasive melanoma and, when invasive, describes Breslow thickness, ulceration, margins, and other relevant features. Borderline or unusual melanocytic lesions can be difficult even for experts, so a second dermatopathology review can be reasonable when different interpretations would materially change treatment.7,8
4. Selective staging information
Not every patient needs scans or a lymph-node procedure. Examination, pathology, symptoms, and risk determine whether more staging is useful.
A sentinel lymph-node biopsy (SLNB) samples the first draining node or nodes to look for microscopic spread. It is a staging and prognostic procedure. It does not remove the primary skin melanoma, and it is not the same operation as a therapeutic dissection of an entire lymph-node basin. The skin melanoma is removed by its own definitive local operation.8–10,12
A realistic example
A patient hears, “We should discuss a sentinel-node biopsy,” and assumes the node procedure will remove the melanoma. The accurate map is: the definitive skin operation treats the primary site; SLNB, when appropriate, samples the first draining node to add staging information. Those procedures may occur during the same anesthetic, but their purposes remain different.
Memorable rule: The skin operation removes the primary. SLNB samples a node.
How do stage, treatment purpose, and urgency fit together?
How Do Stage, Treatment Purpose, and Urgency Fit Together?
Only after in situ versus invasive, Breslow thickness, ulceration, and stage are understood does a treatment overview become useful.
| Broad pattern | What is known | Main treatment purpose | Usual urgency and next conversation |
|---|---|---|---|
| Melanoma in situ / stage 0 | Confined to epidermis | Complete local clearance and prevention of invasion | Timely local treatment planning; surgery is preferred, while selected lentigo maligna or limited-life-expectancy situations may warrant specialist discussion of topical imiquimod, radiation, or observation |
| Localized invasive melanoma | Invasion is present; no regional or distant spread is known | Cure through definitive local control, with risk-appropriate nodal staging when useful | Prompt surgery planning after depth, ulceration, site, and staging needs are reviewed |
| Regional melanoma | Nearby skin, lymphatic, or regional-node spread is present | Control known disease and reduce or treat recurrence risk using a multidisciplinary plan | Timely melanoma-specialist coordination; sequence depends on the exact regional pattern and resectability |
| Distant metastatic melanoma | Spread to distant skin, nonregional nodes, or organs is present | Systemic disease control, longer survival, symptom prevention or relief, and selected local control | Prompt oncology planning; acute symptoms may require urgent assessment |
For most localized invasive melanomas, wide local excision is the usual operation. Staged excision or Mohs surgery can be appropriate for selected tumors—for example, some poorly defined melanoma in situ or selected anatomically constrained cases—but it is not automatically best for every melanoma and is not automatically wrong. For selected lentigo maligna when surgery is not a reasonable fit, specialist-guided topical imiquimod or radiation may be considered; observation is reserved for carefully selected patients in whom functional status, life expectancy, and treatment burden change the balance.9,10,12
Drug therapy, radiation, additional surgery, or clinical trials may enter for selected higher-risk, regional, recurrent, or distant disease. Those choices require the exact stage and belong in the melanoma treatment guide and specialist conversation, not in a diagnosis-basics article.
Read next: Melanoma Treatment Options and Margin Control.
What does melanoma prognosis depend on?
What Does Prognosis Depend On?
Prognosis varies because melanoma varies. Important inputs can include:
- melanoma in situ versus invasive disease;
- Breslow thickness and ulceration;
- regional skin deposits or lymph-node involvement;
- distant metastasis, if present;
- anatomic site and melanoma subtype;
- tumor biology;
- a person’s overall health; and
- response to treatment.1,8,9
Many melanoma in situ and localized invasive melanomas are treated successfully. Some localized invasive melanomas still carry meaningful recurrence risk, while regional and distant disease are not one uniform category. The right question is not “What is the melanoma survival rate?” It is “What does my complete pathology and exact stage mean, and what information is still missing?”
What should I ask or do next about melanoma?
What Should I Ask or Do Next?
Bring the complete pathology report—not just a portal message—and ask:
- Is this definitely cutaneous melanoma, and would expert dermatopathology review change anything?
- Is it melanoma in situ or invasive melanoma?
- If invasive, what is the Breslow thickness? Was the deepest point captured?
- Is histologic ulceration present?
- What do the peripheral and deep biopsy margins mean in this biopsy type?
- What is known about regional nodes or distant spread, and what is my exact stage now?
- Do I need any additional staging information? If SLNB is discussed, what decision would its result change?
- What is the goal of the recommended treatment, and what alternatives fit this tumor and site?
- What is the planned timeline, and which symptoms or changes should make me call sooner?
- Who is coordinating skin surveillance after treatment, including checks for another primary melanoma?
Neutral next actions:
- Save a copy of the pathology report and any addendum.
- Confirm that the clinician who ordered the biopsy has reviewed the result with you.
- Avoid trying to assign your stage or survival percentage from a photograph or a single report word.
- Ask for the melanoma-treatment guide once the pathology branch is clear.
- Return to Step 4: Understand diagnosis in your saved Patient Journey when you are ready to connect these pathology terms to your next decision.
Frequently asked questions about melanoma
Frequently Asked Questions
Does melanoma always start in a mole?
No. In the pooled observational evidence above, most melanomas were classified as de novo—arising without an associated pre-existing nevus. Watch new spots as well as changing moles.2
Is melanoma always black or brown?
No. Melanoma may be pink, red, flesh-colored, or only lightly pigmented. Color is one clue, not a clearance test.5,6
Can a photograph tell whether a spot is melanoma?
No. A photograph may help document change or support triage, but it cannot reliably confirm or exclude melanoma. Diagnosis requires biopsy and microscopic pathology.7,8
If a spot does not meet ABCDE, can it still be melanoma?
Yes. ABCDE is a recognition aid, not a rule-out test. Some melanomas are small, symmetric, evenly colored, or otherwise outside the classic pattern.5,6
Is melanoma in situ really cancer?
It is the earliest anatomic form of melanoma, confined to the epidermis in the examined tissue. A truly in-situ melanoma has not entered the dermis and therefore is not thought to metastasize. Rarely, however, deeper sectioning or additional tissue reveals an invasive focus that was not captured initially. Local treatment remains important because the lesion can enlarge and may become invasive.8–10
Does “invasive” mean the melanoma has spread?
No. It means the melanoma has crossed below the epidermis. It may still be localized to the original skin site. Regional or distant spread requires separate evidence.8,9
Does a clear biopsy margin mean I am finished?
Not necessarily. A biopsy is designed to diagnose and measure the tumor. Definitive local treatment and any staging discussion depend on the full report, the biopsy method, and the clinical site.
Will every patient need a sentinel lymph-node biopsy?
No. The discussion depends on invasive depth, ulceration, other features, and whether the result would change staging or management. It is not used for a truly in-situ melanoma and is not automatic for every invasive melanoma.9,12
Is Mohs surgery appropriate for melanoma?
It can be appropriate in selected situations, including some poorly defined melanoma in situ and selected constrained-site tumors. Wide local excision remains usual for most invasive melanoma. For selected lentigo maligna when surgery is not a reasonable fit, topical imiquimod or radiation may enter a specialist-guided discussion. The correct answer depends on the pathology, border, site, health, and expertise available—not a universal slogan.9,10,12
Can melanoma be cured?
Many melanoma in situ and localized invasive melanomas are treated successfully. The chance of cure is not one number for everyone; it depends on the complete pathology, stage, health, and treatment response.1,8,9
How fast does melanoma grow?
There is no reliable single clock. Some lesions evolve slowly and others more quickly. Do not use lack of symptoms or a short period without visible change as proof that waiting is safe.8–10
Can a person with darker skin develop melanoma?
Yes. Melanoma can occur in every skin tone, including on palms, soles, and nails. Lower average population risk is not zero individual risk.3,6
Where should I go next in the melanoma Patient Journey?
Next Steps in the Patient Journey
Continue with the question that best fits what you know now. Your dermatologist or treating team can apply the complete pathology and examination to your situation.
Continue with the question that fits you now
Who reviewed and authored this melanoma guide?
References for this melanoma guide
References
- National Cancer Institute. SEER Cancer Stat Facts: Melanoma of the Skin. Reproduces the American Cancer Society 2026 projected United States cases and deaths and reports SEER 21 relative-survival data for diagnoses in 2016–2022. https://seer.cancer.gov/statfacts/html/melan.html
- Pampena R, Kyrgidis A, Lallas A, et al. A meta-analysis of nevus-associated melanoma: prevalence and practical implications. J Am Acad Dermatol. 2017;77(5):938-945.e4. PMID: 28864306. DOI: 10.1016/j.jaad.2017.06.149.
- National Cancer Institute. Skin Cancer Prevention (PDQ), Patient Version. https://www.cancer.gov/types/skin/patient/skin-prevention-pdq
- National Cancer Institute. Common Moles, Dysplastic Nevi, and Risk of Melanoma. https://www.cancer.gov/types/skin/moles-fact-sheet
- American Academy of Dermatology. What to look for: ABCDEs of melanoma. https://www.aad.org/public/diseases/skin-cancer/find/at-risk/abcdes
- American Academy of Dermatology. Signs that could be melanoma on your foot. https://www.aad.org/public/diseases/skin-cancer/types/common/melanoma/signs-foot
- American Academy of Dermatology. Melanoma: Diagnosis and treatment. https://www.aad.org/public/diseases/skin-cancer/types/common/melanoma/diagnose-treat
- National Cancer Institute. Melanoma Treatment (PDQ), Patient Version. https://www.cancer.gov/types/skin/patient/melanoma-treatment-pdq
- Gershenwald JE, Scolyer RA, Hess KR, et al. Melanoma staging: evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J Clin. 2017;67:472-492. PMID: 29028110. DOI: 10.3322/caac.21409.
- Swetter SM, Tsao H, Bichakjian CK, et al. Guidelines of care for the management of primary cutaneous melanoma. J Am Acad Dermatol. 2019;80:208-250. PMID: 30392755. DOI: 10.1016/j.jaad.2018.08.055.
- College of American Pathologists. Protocol for the Examination of Biopsy Specimens from Patients with Invasive Melanoma of the Skin. Version 1.1.0.0. March 2025. https://documents.cap.org/documents/New-Cancer-Protocols-March-2025/Skin.Inv_Melanoma.Bx_1.1.0.0.REL.CAPCP.pdf
- National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Melanoma: Cutaneous. Version 2.2026. Updated April 17, 2026.