Subungual melanoma symptoms risks and treatment

Subungual melanoma is a rare type of skin cancer that appears most commonly on the fingers or toes. It can sometimes be difficult to distinguish from normal bruising or nail pigmentation, which often leads to delayed diagnosis. Understanding its symptoms, causes, and available treatment options can help save your life and protect the health of your nails.In this Daleely Medical article, we will explore everything you need to know about this form of cancer, including how to detect it early and the best ways to prevent it.

What Is Subungual Melanoma?

Subungual melanoma is a rare type of skin cancer that develops under the nail due to abnormal growth of pigment-producing cells (melanocytes).

It most commonly appears on the fingers or toes.
In the early stages, it may look like a bruise or a dark streak, which makes early detection difficult.

How Do I Know If a Nail Spot Is Cancer?

You may suspect nail cancer if you notice:

A dark or black vertical line on the nail
Gradual changes in the color or shape of the nail
Any new or unusual discoloration that persists

Any suspicious change should always be evaluated by a dermatologist.

Is Nail Melanoma Dangerous?

Yes. Subungual melanoma is serious because it can spread to surrounding tissues or other organs.

If not detected early, the survival rate can drop from 95% in early stages to about 15% in advanced stages.

Who Is at Higher Risk?

Anyone can develop subungual melanoma, but some groups are more likely to be affected:

Adults aged 50–70 years
Individuals with darker skin
People of African American, Asian, or Latino descent

How Common Is Subungual Melanoma?

It is extremely rare, accounting for only 0.7% to 3.5% of all melanoma cases worldwide.

How Does Nail Melanoma Start?

It usually begins as a small dark streak under the nail.
Over time, the discoloration may widen or develop irregular borders.

You may also notice nail damage such as cracking or lifting, and in later stages, bleeding under the nail.

How Fast Does It Grow?

Subungual melanoma grows slowly over several months.
It does not appear overnight. Changes are usually gradual.

Can Nail Melanoma Spread?

Yes. It can spread to:

The skin around the nail
Nearby tissues
Lymph nodes
Other organs if not treated early

Early diagnosis greatly increases the chance of successful treatment.

Survival Rates

Early detection: up to 95% survival
Late detection with metastasis: about 15% survival

Can Children Get Subungual Melanoma?

It is extremely rare but possible.
It occurs far more often in adults over 50.

Any sudden dark streak in a child’s nail should be checked immediately.

How to Tell the Difference Between a Bruise and Melanoma

Bruises fade within weeks.
Melanoma persists and gradually becomes darker or wider.
It may also cause nail deformities or repeated bleeding.

Stages of Subungual Melanoma

Stage 0 – Melanoma In Situ (Superficial)

Cancer is limited to the top layer of skin under the nail
No spread
Appears as a small dark streak

Treatment: removal of the affected cells.

Stage 1 – Early Localized Melanoma

Cancer begins to invade deeper layers
No lymph node involvement
Symptoms may include a darker streak or mild nail changes

Treatment: removal of part of the nail and surrounding tissue.

Stage 2 – Locally Advanced Melanoma

Tumor becomes thicker and larger
May cause swelling, bleeding, or ulceration
No distant spread yet, but it threatens nearby tissues

Treatment: removal of a larger portion of the nail or finger tissue; sometimes partial amputation.

Stage 3 – Spread to Lymph Nodes

Cancer spreads to nearby lymph nodes
Symptoms include swollen lymph nodes or significant finger/toe pain

Treatment:
Tumor removal + lymph node removal + may include radiation or systemic therapy.

Stage 4 – Distant Metastasis

Cancer spreads to organs such as the lungs, liver, or brain

Treatment: systemic therapies (immunotherapy, targeted therapy, or chemotherapy) along with possible surgery.

Types of Subungual Melanoma

1. Pigmented Melanoma

Most common type
Appears as a dark brown or black streak
The line may widen or change with time

2. Amelanotic Melanoma

Rare and harder to diagnose
No dark pigment—appears pink, red, or pale
Often mistaken for infection or benign lesions

3. Superficial Spreading Melanoma

Common on skin, less common under nails
Starts on the surface and gradually spreads

4. Nodular Melanoma

Rare but very aggressive
Appears as a raised, solid lump
Can be dark or light in color
Grows faster than other types

5. Acral Lentiginous Melanoma

The most common melanoma on nails and extremities
Appears as a dark streak or patch
Common in people with darker skin
Slow-growing at first but can spread

Causes of Subungual Melanoma

1. Sun Exposure

Although the nail protects against UV rays, chronic sun exposure may still contribute.

2. Repeated Trauma

Frequent injuries to the nail can damage melanocytes.
Examples: manual labor, sports, or a severe nail injury.

3. Genetics

Family history of melanoma increases the risk.
Mutations in genes like CDKN2A or BRAF are associated with higher melanoma risk.

4. Skin and Nail Color

More common in individuals with darker skin tones.

5. Age

More common after age 50 due to accumulated cell damage.

6. Prior Nail Disorders

Previous nail infections, chronic inflammation, or abnormal nail growth increase the risk.

Other Possible Factors

Smoking
Weak immune system

Symptoms of Subungual Melanoma

1. Nail Discoloration

A dark line or black/brown streak running along the nail
The streak may start thin and gradually become wider
Sometimes the color appears gray, blue, or reddish

2. Widening or Shape Change of the Streak

The existing line may become wider or change shape
Multiple lines may appear or the pigmentation becomes uneven

3. Changes in the Nail Itself

Peeling or brittleness
Cracking or breaking without a clear cause
Abnormal thickening of the nail

4. Bleeding or Discharge

Bleeding under the nail or dark-colored discharge
The bleeding may resemble a bruise or appear mild

5. Pain or Tenderness

Mild pain or pressure at the base of the nail
Pain may be triggered by touch or pressure

6. Skin Changes Around the Nail

Redness or swelling around the nail
Small sores or changes in the skin around the nail

7. Spread in Advanced Cases

If untreated, the tumor may extend to the surrounding tissues
In later stages, it may spread to lymph nodes or distant organs

Tests Used to Diagnose Nail Melanoma

1. Clinical Examination

The doctor evaluates:

Nail color and shape
Presence of a dark streak or widening pigmentation
Any swelling, pain, or irregularity

A dermatoscope may be used to visualize fine details under the nail.

2. Biopsy (The Definitive Test)

A biopsy is essential to confirm melanoma. Types include:

Punch Biopsy: Removes a small portion of the nail or underlying skin
Excisional Biopsy: Removes the entire nail or a larger section along with suspicious tissue

The sample is examined under a microscope to determine if cancer cells are present.

3. Imaging Tests

Typically used in advanced cases:

X-ray: Checks for bone involvement
MRI: Identifies tumor depth and spread to nearby tissues
CT scan: Detects potential spread to other organs

4. Blood Tests

Not used to diagnose melanoma but may help evaluate overall health or readiness for certain treatments.

5. Sentinel Lymph Node Biopsy

Used for larger or aggressive tumors to check whether melanoma has spread to nearby lymph nodes.

Medical Treatment for Nail Melanoma

1. Targeted Therapy

Used when melanoma cells carry genetic mutations such as BRAF or MEK.

Common medications:

Vemurafenib, Dabrafenib (target BRAF)
Trametinib (targets MEK)

These drugs stop cancer cells from growing and are often used when the cancer has spread.

2. Immunotherapy

Boosts the immune system to attack cancer cells.

Examples:

Pembrolizumab, Nivolumab (PD-1 inhibitors)
Ipilimumab (CTLA-4 inhibitor)

Often used in advanced or treatment-resistant cases.

3. Chemotherapy

Uses drugs such as Dacarbazine or Temozolomide.
It is less commonly used now due to the greater effectiveness of targeted and immune therapy.

4. Adjuvant Therapy (After Surgery)

Given after tumor removal to reduce the risk of recurrence.
The choice of medication depends on:

Tumor genetics
Stage of the disease
Patient’s overall health

Important Tips When Using Medications

Regular follow-up with an oncologist
Routine blood tests to monitor liver, kidney, and blood function
Watch for side effects such as rash, fatigue, or digestive issues
Strict adherence to the treatment schedule to prevent resistance

Treatment Options for Subungual Melanoma

1. Surgical Treatment

A. Partial Nail Plate Excision

Removal of the affected section of the nail and underlying tissue
Used for very early, localized melanoma
Goal: preserve as much of the nail as possible

B. Total Nail Plate Excision

Complete removal of the nail and infected tissue
Used for larger tumors or those involving the nail base
The nail may heal naturally or be protected with a temporary covering

C. Partial or Complete Digit Amputation

Necessary in advanced cases or when cancer reaches the bone
Partial amputation: Removes part of the affected finger/toe
Complete amputation: Removes the entire digit

Goal: ensure full tumor removal and prevent spread.

D. Lymph Node Dissection

Performed if cancer spreads to nearby lymph nodes
Removal of affected nodes to reduce further spread

2. Laser Treatment

Uses Argon or CO2 laser in very early cases.

Destroys abnormal pigment cells without removing the entire nail
Advantages: less pain, faster healing, and better cosmetic outcome
Limitations: not suitable for advanced or deeply invasive melanoma

3. Combined Surgery and Laser Therapy

Used in selected early cases.
Surgery removes most of the tumor, while laser targets remaining cells to reduce recurrence and preserve nail appearance.