Toenail (Subungual Melanoma) Cancer Symptoms

The melanoma is known as the most aggressive (and most dangerous) form of skin cancer. Usually this is a melanoma of the skin, but in some cases, melanoma originating from the nail (toenail). This is referred to as subungual melanoma, which mainly occurs in middle or older age (40 to 70 years). Men and women are affected equally.

How does subungual melanoma develop?
Subungual melanoma, like the melanoma of the skin, is a malignant proliferation of pigment cells. An important risk factor for the development of melanoma of the skin is excessive exposure to ultraviolet (UV) radiation (especially skin burns at childhood). This causal relationship has not yet been demonstrated for subungual melanoma. Nor does it seem to be a relationship with a light skin type; subungual melanoma is just as common in people with an Asian or black skin type. The risk factors for the subungual hematoma have therefore not yet been clarified. Hereditary predisposition and/or trauma (injuries to the nail) may play a role.

What are the symptoms of subungual melanoma?
In a majority of cases, the subungual melanoma manifests as a brown or black band-like discoloration of your nail; also called “longitudinal melanonychia”. Longitudinal melanonychia is common, especially among individuals with an Asian or Black skin type. Usually it is a benign defect, but in about 5% of the cases this phenomenon is based on a (starting) subungual melanoma. Alertness is required, especially if you develop a band-like discoloration at a later age or change an already existing discoloration in terms of size and/or color. Like the melanoma of the skin, the subungual melanoma is not always accompanied by a (brown) discoloration. Other symptoms that may indicate a subungual melanoma are (red) swelling under your nail, (repeated) nail bleeding and / or the spontaneous release of your nail. A striking symptom is also the presence of the “Hutchinson sign”, ie also the skin around the nail is brown or black discolored.

How is subungual melanoma diagnosed?
If your doctor cannot rule out subungual melanoma based on the nail abnormalities, he or she will proceed to a nail biopsy. One or more (affected) pieces of the nail are removed under local anesthesia. These pieces are then examined microscopically for abnormalities appropriate to the subungual melanoma.

How is subungual melanoma treated?
As for the melanoma of the skin, there are different treatment options for the subungual melanoma.

SURGICAL TREATMENT

1. Re-excision. When microscopic examination by the pathologist has shown that you have subungual melanoma, a wider excision of the affected area will be started in the short term. The amount of (potentially affected) tissue to be cut depends on the extent (especially the thickness) and the location of the deviation. If it concerns a subungual melanoma of a toenail, in many cases (except for the big toe), surgical amputation of the entire toe will be chosen. If the subungual melanoma starts from a fingernail, the amputation of the upper phalanx is usually sufficient.
2. Lymph node dissection. If based on physical and/or imaging examination, it is suspected that the subungual melanoma has spread to one or more lymph nodes, a sentinel node biopsy and/or lymph node dissection (examining and/or removing potentially affected lymph nodes, respectively) can be decided. However, the added value of this is controversial, according to recent scientific studies.

NON-SURGICAL TREATMENT
In addition to surgical treatment by a skin doctor and/or surgeon, there are also numerous non-surgical (additional) treatments, including isolation perfusion, radiotherapy, chemotherapy and immunotherapy. Such treatments are not performed by your skin doctor.

What can you do about subungual melanoma yourself?
Adequate sun protection. Although no causal relationship has yet been demonstrated for subungual melanoma with (excessive) exposure to UV radiation, adequate sun protection is of great importance to minimize the risk of melanoma of the skin (and other forms of skin cancer).
Timely recognition. Partly because it is a rare and relatively unknown condition, the subungual melanoma is often recognized by patients too late. Timely recognition is associated with higher healing opportunities. Therefore, consult your doctor if there is a discoloration of the nail that lasts longer than six weeks, has not been preceded by trauma and does not respond to antifungals.

What is the prognosis of subungual melanoma?
Since subungual melanoma is often only recognized by patients at a late stage, the prognosis is still poor. Five-year survival rates range between 16 and 87%, but in the majority of major medical studies, they are around 50%.