Melanoma on the Nail and Foot: Acral Melanoma, Signs and Causes

Acral (acrolentiginous, subungual) melanoma is a variant of cutaneous melanoma, the most serious form of skin cancer. Melanoma is a malignant tumor arising from melanocytes, the pigment cells. Below we explain how the acrolentiginous form is distinguished, what signs are described, and how a doctor makes the diagnosis.

What melanoma on the nail and acral melanoma are

Melanoma is a malignant tumor arising from melanocytes, the pigment cells that produce melanin. Most often it develops in the skin, less often in the retina of the eye and on mucous membranes. The peculiarity of melanoma is that the body hardly reacts to it, so the tumor often progresses rapidly and metastasizes via lymphatic and hematogenous routes to almost all organs.

Acrolentiginous melanoma is known as subungual melanoma and grows on the tips of the fingers and on the palms. The subungual form is described as a separate clinical type.

Acral lentiginous melanoma: how it differs

In clinical classifications, acrolentiginous melanoma (Acral Lentigo Maligna) accounts for about 10% of cutaneous melanoma cases. It grows on the tips of the fingers and on the palms, and it occurs most often in dark-skinned people. This distinguishes it from the superficial spreading form (about 70% of cases, more often in women) and nodular melanoma (about 15%, more often in men).

What melanoma under the nail, on the toe, foot and palm looks like

The first sign of melanoma in general is a change in the size, shape, color or sensations of a mole. Most melanomas have a black or black-blue area, and they may look like a new mole — black, irregular, "ugly."

• Asymmetry: one half does not match the other.
• The edge is uneven, blurred or jagged.
• The color is uneven, with shades of black, brown and beige.
• The diameter changes, usually increasing.
• Changeability: the spot changes over the past weeks or months.

Itching, hair loss from the surface, ulceration, bleeding and nodule formation in the area of the nevus are described separately.

Why nail melanoma occurs and who is at risk

The leading risk factor is ultraviolet radiation: from the sun and from tanning equipment. Ionizing radiation and a history of radiation burns, fair skin, blue eyes, blond hair and freckles, and past sunburns are also cited. Dysplastic nevi, a family history of melanoma, more than 50 moles, xeroderma pigmentosum, previously treated melanoma and age over 50 years matter. In people with diabetes, a tumor on the foot is sometimes confused with diabetic foot ulcers.

How nail melanoma is diagnosed

The earliest method is dermatoscopy: examination through a magnifying glass or a dermatoscope, which makes the stratum corneum of the epidermis transparent. The doctor evaluates the lesion using the ABCDE system proposed in 1985. Computerized microdermoscopy systems raise the level of early diagnosis from 60% to 90%, but often only in experimental settings. The final diagnosis is made only after a histological examination.

When a spot or streak on the nail is a reason to see a doctor urgently

Any pigmented lesion that changes is a reason to visit a doctor: it grows, darkens unevenly, itches, ulcerates or bleeds. Such a lesion is evaluated by a doctor.

A spot or streak on the nail or foot by itself is not a reason to call an ambulance. 103/112 — for a life-threatening condition, for example signs of stroke or heart attack, or severe injury.

This material is for reference: it explains what can occur and what a doctor evaluates, but it does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer