Subungual melanoma is a rare form of skin cancer that attacks the nails. Although it can attack any nail, it is more prevalent in the toenail or thumbnail. Dark-skinned ethnic groups, with a prevalence of 15% - 35%, tend to get it more than Caucasians (prevalence 3%).
The main symptom of subungual melanoma is pigmentation under the affected nail. This usually occurs as a pigmented stripe that runs under the nail. The clinical term for the pigmentation is Hutchinson's sign, and it tends to be wider at the base of the nail than the edge of the nail.
The stripe starts out small and widens with time. In fact, it can widen so much that it turns to a lesion. If you delay treatment, then the lesion will turn into a serious ulcer that may even uproot and lift your nail.
The problem with subungual melanoma symptoms is that there are other nail conditions that mimic it. For example, a nail that has suffered physical trauma (such as hitting your nail with a hammer) may also develop pigmentation under it. Therefore, when you develop such coloration, you should remember if there is any history of physical trauma on the nail.
Longitudinal melanonychia is another nail condition that you can mistake for subungual melanoma. This is a benign (noncancerous) nail condition caused by a variety of conditions, such as inflammatory skin diseases, endocrine disorders, and medications.
The main difference between these conditions and subungual melanoma is that the latter changes with time. The pigmented stripe of the nail cancer gets wider and darker with time, but this inst the case if the stripe is caused by physical trauma or longitudinal melanonychia.
Still, you shouldn't wait to see whether your stripe is changing or note before consulting an oncology doctor. Just like other forms of cancer, subungual melanoma can spread to other parts of the body. This means you need to have it diagnosed early and treated before it spreads.
What to Watch Out For
Since the condition is not painful in its early stages, the only way to catch it early is to examine your nails periodically. This may not be easy if your nail is always covered in polish or other forms of cosmetic treatments. Therefore, remove the treatments regularly and examine your nails for any changes.
Surgical excision (removal of the affected tissues) is the usual treatment for subungual melanoma. The more the disease has spread, the more of your tissues will be removed. Therefore, it's essential to seek early treatment.