Subungual & Nail Melanoma: Signs, Pictures & Treatment

Subungual melanoma is a rare but serious type of melanoma that occurs under the nail. It is often misdiagnosed as a bruise or fungal infection, leading to delayed treatment. This article provides a comprehensive overview of this condition, including its signs, pictures, and treatment options, to help you recognize early warning signs and seek timely medical intervention.

Also known as nail melanoma or ungual melanoma, it can affect both fingernails and toenails. Although it accounts for only a small percentage of all melanomas, it is the most common type in people with darker skin tones. Understanding the symptoms and risk factors is crucial for early detection and successful treatment.

What Is Subungual Melanoma?

Subungual melanoma originates in the nail matrix, the area at the base of the nail where new nail cells are produced. It can appear as a dark streak or discoloration under the nail. Unlike other skin cancers, it often goes undetected because it resembles common nail injuries. The most common site is the thumb or big toe, but it can occur in any nail.

The condition is often associated with a history of trauma, but no direct causal link has been established. It is more common in older adults and in individuals with darker skin. Early diagnosis is vital because melanoma can spread to other parts of the body if not treated promptly.

Signs and Symptoms of Nail Melanoma

The most common sign is a brown or black streak under the nail, known as longitudinal melanonychia. This streak typically appears as a vertical band that runs from the cuticle to the tip of the nail. However, not all dark streaks are melanoma; many are benign. The following signs should raise suspicion:

• Dark streak that is wider than 3 mm or has irregular borders.
• Discoloration of the nail bed that spreads to the surrounding skin (Hutchinson's sign).
• Nail splitting or cracking of the nail plate.
• Bleeding or ulceration under the nail without trauma.
• Pain or tenderness in the nail area.

It is important to note that subungual melanoma can also be amelanotic (lacking pigment), appearing as a red, pink, or flesh-colored growth. This variant is often misdiagnosed as a wart or infection, leading to delays in diagnosis.

Nail Melanoma Pictures: What to Look For

Visual examination is a key part of diagnosis. Typical nail melanoma pictures show a dark, longitudinal band that may be irregular in color and width. However, it can be difficult to distinguish from benign conditions like a subungual hematoma (blood under the nail) or fungal infection. The following characteristics in pictures may indicate melanoma:

• Streak that is black, brown, or has multiple shades of color.
• Presence of Hutchinson's sign – pigmentation extending onto the cuticle or surrounding skin.
• Nail dystrophy – thickening, splitting, or absence of the nail plate.

If you compare nail melanoma pictures from medical sources, you'll notice that the pigment often originates from the nail matrix and extends outward. In advanced cases, the nail may be destroyed or there may be a visible nodule. It is important to have any suspicious lesion examined by a dermatologist who may use dermoscopy to assess the pattern.

Causes and Risk Factors

The exact cause is unknown, but several risk factors increase the likelihood:

• Genetics: Family history of melanoma or other skin cancers.
• Trauma: History of injury to the nail, though it is not a direct cause.
• Age: Most common in people over 50 years old.
• Skin type: More common in individuals with darker skin tones.
• Existing moles: Previous melanoma or atypical moles.

Diagnosis of Subungual Melanoma

Diagnosis begins with a thorough clinical examination, including dermoscopy. If the lesion appears suspicious, a biopsy is necessary. The biopsy involves removing a small sample of the nail matrix or the pigmented lesion for histopathological analysis. The dermatopathologist will look for atypical melanocytes invading the nail bed.

Staging follows the same system as other melanomas, based on tumor thickness (Breslow depth), ulceration, and spread to lymph nodes or distant sites. Early-stage melanoma is confined to the nail unit, while advanced stages indicate deeper invasion or metastasis.

Treatment Options for Nail Melanoma

Treatment depends on the stage and extent of the disease. The primary treatment is surgical excision with clear margins. For early-stage melanoma, wide local excision of the nail unit may be sufficient. This often involves removing the entire nail, nail bed, and part of the surrounding skin. In some cases, amputation of the digit may be necessary if the melanoma is deep or has spread to the bone.

For advanced melanoma, additional treatments may include:

• Sentinel lymph node biopsy to check for spread.
• Immunotherapy such as checkpoint inhibitors (e.g., pembrolizumab).
• Targeted therapy for melanomas with BRAF mutations.
• Radiation therapy for local control or palliation.

Chemotherapy is rarely used for melanoma today. Clinical trials may also be available for patients with advanced disease. Early-stage subungual melanoma has a good prognosis when treated promptly, with five-year survival rates above 90% for thin lesions. However, delayed diagnosis can lead to poorer outcomes.

Prognosis and Survival Rates

The prognosis for subungual melanoma is generally poorer than for cutaneous melanoma because of delayed diagnosis. The five-year survival rate for localized disease is around 80%, but drops to 50% or less if the melanoma has spread to lymph nodes. Factors that worsen prognosis include older age, higher Breslow thickness, ulceration, and presence of metastasis.

Regular follow-up is essential after treatment. Patients should perform monthly self-exams of their nails and skin, and have annual dermatological checks. Any new or changing nail pigmentation should be evaluated promptly.

Differential Diagnosis: What Else Could It Be?

Many conditions can mimic subungual melanoma. The most common is subungual hematoma (blood under the nail) from trauma. Unlike melanoma, a hematoma often moves as the nail grows and may have a rounded shape. Other mimics include:

• Fungal infections – can cause discoloration and thickening.
• Benign nevi (moles) under the nail.
• Lentigo – a benign pigmented lesion.
• Medications – certain drugs can cause nail pigmentation.

A dermatologist with expertise in nail disorders can often differentiate these using dermoscopy. If uncertainty remains, a biopsy is the gold standard for diagnosis.

Prevention and Early Detection

While there is no guaranteed way to prevent subungual melanoma, early detection is key. The ABCDE rule for melanoma detection can be adapted for nail lesions: A for asymmetry, B for irregular borders, C for color variation, D for diameter >6 mm, and E for evolution (change over time). Additionally, the “EFG” rule for nail melanoma highlights Elevation, Firmness, and Growth.

If you have a family history of melanoma or multiple atypical moles, consider regular dermatological screenings. Protect your hands and feet from UV exposure with sunscreen or gloves, although UV is not a strong risk factor for subungual melanoma. Most importantly, do not ignore any persistent nail changes.

Living with Nail Melanoma: Support and Resources

A diagnosis of nail melanoma can be overwhelming. It is important to seek support from medical professionals, family, and support groups. Organizations like the Melanoma Research Foundation and Skin Cancer Foundation provide valuable resources for patients. After treatment, some patients may experience changes in nail appearance or function, but many adapt well.

Advances in immunotherapy and targeted therapy have improved outcomes for advanced melanoma. If you are diagnosed with subungual melanoma, discuss all treatment options with your oncologist, including clinical trials. Remember that you are not alone, and there is hope for recovery.