Melanoma

Melanoma is a skin cancer that starts in the cells that give skin its color. It has a serious reputation, and that reputation is earned — of the common skin cancers, melanoma is the one most able to spread. But there's a reassuring other half to the story: most melanomas are found early, and when they are, a single outpatient surgery cures the large majority of them.

This guide walks through what melanoma is, how it's found, and what treatment usually looks like — in plain terms first, with the deeper detail further down for anyone who wants it.

Key points

• Melanoma is serious because it can spread — but most cases are caught early, when a simple surgery cures the large majority.¹²
• Outlook depends more on how early it's found than on almost anything else.²
• For most early melanomas, treatment is a single surgical removal, often in the office — not chemotherapy.³
• A new or changing mole is the most important warning sign. When in doubt, get it checked.

If you've noticed a spot that's new, changing, or just doesn't look like your others, it's worth having it looked at — that's exactly what a skin check is for.

What is melanoma?

Melanoma begins in melanocytes — the cells that produce the pigment that colors your skin. It most often appears on the skin, and it can develop in an existing mole or as a new spot. Less commonly, it can arise in the eye or in other areas.

It is far less common than basal cell carcinoma or squamous cell carcinoma, the everyday skin cancers driven by sun exposure. What sets melanoma apart is not how often it occurs but its ability to spread beyond the skin if it isn't caught in time. In 2025, an estimated 104,960 Americans were diagnosed with invasive melanoma.¹ Florida, with year-round high UV, ranks among the highest states for it.

How serious is it?

Melanoma's seriousness is almost entirely a question of timing. The relevant measure is how deep the melanoma has grown into the skin — thin, early melanomas behave very differently from ones that have had time to grow.

Put in terms of 5-year relative survival:

• Found early, while still confined to the skin (localized): about 99%.²
• After it reaches nearby lymph nodes (regional): about 75%.²
• After it spreads to distant organs (distant): about 35%.²

The gap between those numbers is the whole reason dermatologists press so hard on early detection. The same disease, caught at two different moments, has dramatically different outcomes — and catching it early is something largely within reach through regular skin checks.

Signs to watch for

Most melanomas announce themselves as a new mole or a change in an existing one. The classic guide is the ABCDE rule:

• A — Asymmetry: one half doesn't match the other
• B — Border: irregular, ragged, or blurred edges
• C — Color: more than one color, or uneven color
• D — Diameter: larger than a pencil eraser (about 6 mm), though some are smaller
• E — Evolving: any change in size, shape, or color, or a new symptom like itching or bleeding

Not every melanoma follows these rules. Nodular melanoma can appear as a fast-growing firm bump, and amelanotic melanoma has little or no color. The most reliable instinct is the "ugly duckling" — a spot that simply looks or behaves differently from your other moles. When something stands out, have it checked rather than watched.

How melanoma is diagnosed

Diagnosis is straightforward and starts in the office:

1. Skin examination, often with a dermoscope — a handheld magnifier with polarized light that reveals structures beneath the surface.
2. A full-body skin exam, since melanoma can appear anywhere, including less-visible areas.
3. A biopsy if a spot is suspicious — a sample is examined under the microscope. This is the only way to confirm melanoma.⁴

If melanoma is confirmed, the pathologist measures its thickness (Breslow depth) — how far it has grown into the skin. Thickness is the single most important predictor of behavior and guides what happens next.⁵

What treatment usually looks like

For most people, this is the reassuring part. The great majority of melanomas are found early, and early melanoma is treated by surgically removing it — the lesion plus a margin of normal-looking skin around it — usually as an outpatient procedure under local anesthesia. For early-stage disease, that surgery alone is often curative, and no chemotherapy is involved.³

More advanced melanoma is treated more intensively and usually involves a broader care team — for example, checking nearby lymph nodes, and medicines (immunotherapy or targeted therapy) that have meaningfully improved outcomes in recent years.³ If that applies to you, your dermatologist coordinates with a cancer team, and the options are laid out below.

Reducing your risk

You can't eliminate melanoma risk, but you can lower it and improve the odds of catching it early:

• Protect your skin from UV — broad-spectrum SPF 30+, shade during peak hours, and protective clothing.⁶
• Avoid tanning beds, which directly damage skin-cell DNA.⁶
• Check your own skin monthly for new or changing spots.
• See a dermatologist for regular skin checks. For people with many moles, total body photography creates a baseline of your skin to help track changes over time.

One honest note: nicotinamide (vitamin B3), which has good evidence for preventing non-melanoma skin cancers, is not established as a way to prevent melanoma. Sun protection and early detection remain the foundation.

When to see a doctor

Have a spot looked at promptly if it is new, changing, or different from your other moles — or if it bleeds, itches, or won't heal. You don't need to wait for your annual exam, and you don't need a referral. If a spot is on your mind, that's reason enough to book a skin check.

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Compare treatment options

The detail below is for readers who want to go deeper. Most people are well served by the plain summary above — your own treatment is always decided with your dermatologist.

Which treatment is used depends on the stage — how deep the melanoma is and whether it has spread. The options below describe what the evidence and guidelines support; they aren't a recommendation for any individual.

Melanoma in situ (Stage 0 — confined to the top layer)

• Wide local excision — first-line. Surgical removal with 0.5–1.0 cm margins; typically curative, done in the office under local anesthesia.⁴
• Margin-controlled (staged) excision — alternative. Used mainly for the lentigo maligna type on cosmetically sensitive sites like the face or ears, where sparing tissue matters.⁴
• Topical imiquimod — alternative (off-label). An immune cream considered when surgery isn't practical, mainly for the lentigo maligna type; cure rates are lower and it needs close follow-up.⁴
• Radiation — reserved. An option when surgery isn't possible.⁴

Localized invasive melanoma (Stage I–II)

• Wide local excision with stage-based margins — first-line. Margins widen with thickness.⁴
• Sentinel lymph node biopsy — considered for thicker or higher-risk melanomas, to check whether nearby nodes are involved and refine staging.³

Regional melanoma (Stage III — reached nearby lymph nodes)

• Surgery to address the primary site and involved nodes, plus adjuvant therapy — immunotherapy, or targeted therapy if the tumor carries a BRAF mutation — to lower the chance of return.³

Advanced / metastatic melanoma (Stage IV)

• Systemic therapy — immunotherapy (checkpoint inhibitors) or BRAF/MEK targeted therapy — is the mainstay, sometimes with surgery or radiation for specific sites, and clinical trials are often worth discussing. These are managed with a medical oncology team.³

The evidence behind this

Melanoma care is guided by well-established national guidelines and a staging system (AJCC, 8th edition) built on large datasets, in which tumor thickness (Breslow depth) is the central prognostic factor.⁵ Surgical margins, the role of sentinel node biopsy, and the use of imiquimod or radiation for in situ disease follow the American Academy of Dermatology's guidelines of care.⁴ Stage-by-stage treatment reflects current American Cancer Society summaries.³ Survival figures are 5-year relative survival from national cancer statistics and shift as treatments improve, especially for advanced disease.²

Frequently asked questions

Is melanoma curable? Most melanomas found early are cured by surgery alone. The earlier it's caught, the higher the chance of cure — which is why a changing mole should be checked promptly.

Does melanoma always spread? No. Melanoma caught early — while still thin or in situ — usually has not spread and is removed completely with surgery. The risk of spread rises the deeper it grows.

Will I need chemotherapy? Usually not. Early melanoma is treated with surgery. Advanced melanoma is treated mainly with immunotherapy or targeted therapy rather than traditional chemotherapy.

What does an early melanoma look like? Often a new or changing mole that is asymmetric, has an irregular border, varies in color, is larger than a pencil eraser, or is evolving. Some don't fit this pattern, so any spot that looks different from your others is worth checking.

Written by Tyler Long, DO. Last updated June 2026.

References

1. American Cancer Society. Key Statistics for Melanoma Skin Cancer. 2025. cancer.org ↩ ↩²

2. American Cancer Society. Survival Rates for Melanoma Skin Cancer, by Stage. 2025. cancer.org ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. American Cancer Society. Treatment of Melanoma Skin Cancer, by Stage. 2024. cancer.org ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

4. 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. jaad.org ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

5. Gershenwald JE, Scolyer RA, Hess KR, et al. Melanoma staging: Evidence-based changes in the AJCC eighth edition cancer staging manual. CA Cancer J Clin. 2017;67(6):472–492. doi:10.3322/caac.21409 ↩ ↩²

6. American Academy of Dermatology Association. Skin cancer prevention. aad.org ↩ ↩²