Subungual melanoma, also called nail node cancer, is a type of cancer that occurs in the tissues of the nail bed. Melanoma is a type of cancer that develops in cells called melanocytes. Melanocytes are cells that make melanin, the pigment that gives skin, hair, and eyes its color.
Although subungual melanomas are most common on the big toe or big toe , they can appear on any of the fingernails or toes. They are often mistaken for a fungal infection due to the characteristic changes in the color and texture of the nails.
Subungual melanoma is a relatively rare condition, affecting 0.7% to 3.5% of people with malignant melanomas worldwide, and is generally more common in darker-skinned people, including African-American, Asian populations. and Hispanic. It is also more common in older people, between the ages of 60 and 70 for women .
Subungual melanomas usually appear as dark stripes that extend longitudinally (perpendicular to the cuticle). About half of these stripes are brown, blue, or black, and the other half are unpigmented.
As the cancer progresses, new stripes may appear, often of different colors. Over time, the part closest to the cuticle can widen.
Hutchinson's sign is a common finding in most subungual melanomas. This refers to the appearance of a strip that runs from the top of the nail to the nail bed and the cuticle itself.
This helps distinguish it from other nail-related conditions in terms of smoothness, longitudinal discoloration, and cuticle damage.
As the melanoma continues to grow, it can cause bleeding, nodules, or deformities in the nail itself .
While we don't yet know what causes subungual melanoma, we do know about many of the risk factors associated with its development. These include:
- Previous injury to fingers or toes (common finding)
- Personal or family history of melanoma.
- Multiple moles
- Genetics, such as hereditary xeroderma pigmentosa (extreme sensitivity to ultraviolet radiation)
- Suppression of immunity, including in organ transplant recipients and people with advanced HIV
The only thing that is not a factor, and distinguishes it from all other types of melanoma, is exposure to the sun. Ultraviolet (UV) radiation does not promote or accelerate the development of a subungual tumor.
The diagnosis of subungual melanoma is usually made by careful examination of the nail and the lesion. Dermatologists will use a tool called a dermoscope, which provides a magnified view of the nail and the surrounding tissue.
Ultimately, visual inspection has its limitations, especially since subungual melanoma is rare. As a result, it is often mistaken for other more common conditions, such as :
- Subungual hematoma, a hematoma under the nail that does not have the homogeneity of subungual melanoma.
- Fungal infections (onychomycosis) , which often have dark, non-longitudinal stripes accompanied by yellow or white stripes.
- Moles (nevi), which are less likely to appear in stripes
- Melanin deposits under the nail, which can result from pregnancy (as well as chemotherapy or radiation therapy)
A definitive diagnosis can only be made with a biopsy . An excisional biopsy is usually done to remove all of the lesion and some of the surrounding tissue. If the signs are not clear, a less invasive needle biopsy can be used.
Depending on the size and depth of the subungual melanoma, further tests will be required to determine the stage of the disease. As with other forms of cancer, the stage can range from carcinoma in situ (precancerous period) to stage 4 metastatic disease (when the cancer has spread to other organs).
To determine if the melanoma has metastasized, an oncologist can perform a variety of tests, including biopsy of the sentinel lymph nodes (the nodes closest to the tumor) and imaging techniques such as computed tomography (computed tomography) or CT scan. positron emission (PET). …
In recent years, the treatment of subungual melanoma has changed significantly. In the past, amputation of the entire toe or toe was considered the method of choice.
Today, many subungual melanomas are treated more conservatively, removing only the local tumor. When amputation is indicated, it often affects only the first joint closest to the nail. For toenails, second joint amputation is more common.
A 2014 review of the medical literature found that a more conservative approach can work just as well as a full amputation. Also, complete amputation has not been shown to improve survival time in people with subungual melanoma.
Progressive subungual melanoma may require other therapies, including :
- Chemotherapy given systemically through a vein or directly into a tumor.
- Radiation therapy, used primarily as palliative treatment to relieve pain.
- Immunotherapy , a new form of cancer treatment that aims to stimulate the immune system to fight cancer cells.
- Targeted therapies, such as drugs that can target BRAF mutations , which occur in 50% of melanomas .
Response to treatment can vary depending on the stage of the cancer. Results for people with subungual melanoma are generally worse than for other types of melanoma, often due to delays in diagnosis and treatment. The 5-year survival rate for stage IV subungual melanoma is 15% to 20% .
This only emphasizes the need to take action if you find any changes in your nails or skin that appear abnormal or do not improve. Early intervention is the surest way to achieve treatment success.
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If you have been diagnosed with subungual melanoma, it is important to find a specialist with experience in the condition. Subungual melanomas are rare and lack of experience can lead to an overly aggressive treatment approach.
While there should be a great care team around you, you are still the most important aspect of that team. Learn all you can about your cancer. Ask for and accept help. Join supportive online communities that can share your experiences and ideas.