Periungual melanoma: what to know

Melanoma can begin in the nail unit, the skin around the nail, or the tissue under the nail. It may look like a brown or black band, a mark that widens, pigment extending onto nearby skin, a split nail, or a persistent area that does not behave like a bruise. Not every nail mark is melanoma; injury, infection, and other pigment changes can look similar. Examination and a biopsy are often needed to identify the cause.

Book a dermatology assessment for a new, changing, or unexplained nail mark. Bring photographs showing how it has changed and mention any injury, medicines, or family history of melanoma. If testing confirms melanoma, treatment is planned according to its depth, location, and spread. Options may include surgical excision, wider skin-cancer surgery, or other specialist treatment. Do not cover the mark with cosmetic polish before assessment if this makes examination harder.

Arrange prompt review for pigment that is widening, irregular, bleeding, painful, or spreading onto the surrounding skin. Seek urgent help if a treated area becomes rapidly swollen, drains pus, or you develop severe illness. New neurological symptoms in someone with known advanced melanoma require emergency assessment.

Ask whether a biopsy is needed, what the pathology shows, whether nearby lymph nodes need assessment, which operation is appropriate, and how follow-up will be organised.