Skin Cancer and Melanoma: Symptoms, Causes, and Treatment

Melanoma is a dangerous form of skin cancer that starts in melanocytes (pigment cells). While less common than other skin cancers, it's more likely to spread if not caught early. Look for changing moles or new growths using the ABCDE rule: Asymmetry, Border irregularity, Color variations, Diameter larger than a pencil eraser, and Evolution over time. Early detection leads to excellent treatment outcomes, so regular skin checks are crucial.

In plain words

Melanoma is a serious type of skin cancer. It starts in cells that give skin its color. It's less common than other skin cancers but can spread faster. Look for new spots or moles that change using the ABCDE rule: Asymmetry (one half doesn't match the other), Border (ragged edges), Color (different shades), Diameter (bigger than a pencil eraser), and Evolving (changing size or shape). UV rays from the sun or tanning beds cause most melanomas. Light skin, many moles, and family history raise your risk. Doctors treat it by removing it early. If it spreads, stronger treatments like immunotherapy help. Checking your skin often and seeing a doctor for changes leads to the best results.

What is Skin Cancer and Melanoma: Symptoms, Causes, and Treatment?

Symptoms

Early symptoms

Asymmetrical mole: When one half of a mole doesn't match the other half in size, shape, or color. Normal moles are usually symmetrical. Melanomas often grow unevenly. (2) (9)
Irregular borders: Edges that are ragged, notched, or blurred instead of smooth. The pigment may spread into surrounding skin giving a blurred outline. (2) (5)
Color variations: Different shades of brown, black, or sometimes pink, red, white or blue within the same mole. Benign moles usually have a single shade. (9) (5)
Diameter larger than 6mm: While melanomas can be smaller when first detected, most are larger than the size of a pencil eraser (about 6mm) when diagnosed. (2)
Evolving appearance: Any change in size, shape, color, or elevation of a spot on your skin, or any new symptom like bleeding, itching, or crusting. (9) (5)
New unusual growth: Any new spot on skin that looks different from all your other moles (the 'ugly duckling' sign), even if it doesn't match typical ABCDE features. (2) (9)

Serious or emergency symptoms

Bleeding or oozing mole: A mole that develops an open sore that doesn't heal or begins crusting, oozing, or bleeding. This suggests the melanoma is growing through skin layers. See a dermatologist within 1-2 weeks. (5) (9)
Painful skin lesion: A mole that becomes tender or painful suggests possible deeper invasion. Melanomas are usually painless in early stages. Schedule a dermatology appointment promptly. (5)
Swollen lymph nodes: Hard, swollen lymph nodes — especially near an area with a changing or suspicious mole — could indicate cancer spread and needs urgent evaluation. Contact your doctor immediately. (5)
Systemic symptoms: Unexplained weight loss, persistent headaches, bone pain, or chronic cough could indicate advanced melanoma with distant spread (metastases). Seek urgent medical care. (5)

Causes

Primary causes

UV radiation damage: Most melanomas are caused by ultraviolet (UV) radiation from the sun or tanning beds that damages skin cell DNA. This damage accumulates over years. (1) (3)
Genetic mutations: Inherited mutations in genes like CDKN2A or BRAF can increase melanoma risk. Sometimes these mutations occur spontaneously during cell division. (1)
Weakened immune system: People with reduced immune function from medications, illnesses like HIV, or organ transplants have higher melanoma risks. (3)

Risk factors

Sun exposure history

Frequent sunburns (especially blistering childhood burns), living in sunny climates, or using tanning beds dramatically increase melanoma risk. (3) (10)

Fair skin traits

People with fair skin that burns easily, light-colored eyes, red or blond hair, and freckles have higher risk, though melanoma can occur in all skin tones. (3)

Family history

Having a close blood relative with melanoma increases your risk about two to three times compared to people without a family history. (1)

Many or unusual moles

People with more than 50 ordinary moles or any atypical (dysplastic) moles that appear irregular have increased melanoma risk. (3) (10)

Diagnosis

Melanoma diagnosis begins with a thorough skin exam where a dermatologist checks all moles and spots for concerning features using the ABCDE rule. If a suspicious lesion is found, a biopsy (sample removal) is performed to examine cells under a microscope. If melanoma is confirmed, further imaging like CT, MRI, or PET scans may check for spread. The biopsy provides important details about thickness and growth pattern that guide treatment decisions. Early detection by regular self-exams and professional skin checks leads to the best outcomes.

Visual skin exam

A dermatologist inspects all areas of skin (including scalp, between toes, etc.) using bright light and magnification to detect suspicious lesions. (4) (7)

Dermoscopy

A handheld magnification tool (dermatoscope) helps doctors examine skin lesions more clearly than with the naked eye alone. (7)

Skin biopsy

Removing part or all of a suspicious mole to examine under a microscope. Different biopsy types (punch, excisional, shave) may be used based on lesion characteristics. (7)

Sentinel lymph node biopsy

For thicker melanomas, this checks whether cancer has spread to nearby lymph nodes by injecting dye near the tumor and removing the first few nodes reached. (7)

Treatment

Medication options

Immunotherapy drugs

Boosts the immune system's ability to recognize and destroy melanoma cells. They're used for advanced melanoma that has spread or can't be surgically removed. (6) (8)

Targeted therapy

Targets specific genetic mutations (like BRAF) in melanoma cells that help them grow. These are only used when tumors test positive for the mutation. (6) (8)

Chemotherapy

Traditional chemotherapy is less commonly used for melanoma now but may help some patients when other treatments aren't options. (6)

Lifestyle and self-care

Daily sunscreen use: Apply broad-spectrum SPF 30+ sunscreen to all exposed skin 15-30 minutes before going outside. Reapply every 2 hours and after swimming/sweating. Look for water-resistant formulas. (3) (10)
Protective clothing: Wear hats with wide brims, long-sleeved shirts, pants, and UV-blocking sunglasses when outdoors. Darker, tightly woven fabrics block more UV than white or loose knits. (10)
Shade strategy: Seek shade during peak sunlight hours (10am-4pm in most locations). Remember UV rays can pass through clouds and reflect off water, sand, and snow. (3)
Regular skin self-exams: Check all moles monthly using mirrors or a partner's help for hard-to-see areas. Photograph concerning spots to track changes over time. (4) (9)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

Local recurrence: Melanoma can return at or near the original tumor site if not completely removed. This risk is higher with thicker tumors or incomplete margins. (6)
Metastatic spread: Melanoma can spread through lymph nodes to other organs (commonly lungs, liver, brain, or bones). Prognosis worsens with distant metastasis. (6)
Secondary melanomas: People who've had one melanoma are at increased risk for developing new primary melanomas elsewhere on their body. (6)
Scarring & disfigurement: Surgical removal of larger melanomas may require skin grafts or flaps, leaving noticeable scars depending on location and size. (6)

When to see a doctor

Routine follow-up

Schedule annual full-body skin checks with a dermatologist if you have risk factors like fair skin, many moles, or family history of melanoma. (4)
See a dermatologist within a few weeks if you notice any new mole or existing mole that's changing according to the ABCDE warning signs. (7) (4)

Seek emergency care

Seek immediate care for a mole that begins bleeding profusely or won't stop bleeding after applying pressure for 10 minutes. (7)
Get emergency evaluation if you have a history of melanoma and develop neurological symptoms like severe headaches, seizures, or vision changes, which could indicate brain metastasis. (7)

Frequently asked questions

How common is melanoma?

Melanoma accounts for about 1% of skin cancers but causes most skin cancer deaths. In the U.S., nearly 100,000 new melanomas are diagnosed annually. While less common than basal or squamous cell carcinomas, melanoma rates have been rising for decades. It's one of the most common cancers in young adults (especially women under 30). (1) (5)

Can melanoma be cured?

When detected early (before spreading), surgical removal often cures melanoma completely with excellent long-term survival rates (over 99% for very early cases). Even thicker melanomas confined to the skin are frequently cured by surgery alone. Advanced melanomas that have spread require more intensive treatment but can sometimes be controlled long-term with newer therapies. (6) (8)

What does early melanoma look like?

(2) (9)

How fast does melanoma grow?

Growth rates vary. Superficial spreading melanoma may grow slowly over years before penetrating deeper. Nodular melanoma (15-20% of cases) grows rapidly over weeks to months. Any mole that changes noticeably within a few weeks or months needs immediate evaluation. Some melanomas develop abruptly as new lesions rather than from existing moles. (5) (1)

Can darker-skinned people get melanoma?

Yes, while melanoma is more common in fair-skinned people, it can occur in individuals of any skin tone. In darker skin, melanomas often appear in less sun-exposed areas like palms, soles, under nails, or mucous membranes, making them harder to notice. Everyone should perform regular skin self-exams regardless of skin color. (1) (3)

References

CDC — What Is Melanoma? source 1
CDC — Signs and Symptoms of Melanoma source 2
CDC — Skin Cancer Prevention source 3
CDC — Skin Cancer Screening source 4
NHS — Melanoma skin cancer source 5
NHS — Melanoma skin cancer - Treatment source 6
NHS — Melanoma skin cancer - Diagnosis source 7
MedlinePlus — Melanoma source 8
AAD — How to spot skin cancer source 9
AAD — Skin cancer prevention source 10