What should you know about finger nail melanoma?

Pigment under a fingernail may be brown or black, uneven in colour, wider toward the base, or gradually changing. Pigment can also spread onto the adjacent skin, and the nail may split, lift, or become distorted. An injury, mole, medication, or benign pigment condition can look similar, so a dark mark does not establish melanoma by itself. However, a new or evolving streak should be assessed by a dermatologist. Learn more about [Melanoma](/conditions/melanoma/).

Arrange a dermatology appointment and take clear photos in consistent lighting while waiting, without delaying care. Do not cover a changing streak with polish or repeatedly scrape the nail. The clinician may examine the nail unit and recommend a biopsy or [Surgical Excision](/treatments/surgical-dermatology/excisional-surgery/) to identify the cells involved. If melanoma is confirmed, further planning may include [Skin Cancer Surgery](/treatments/surgical-dermatology/skin-cancer-surgery/), [Tumour Removal Surgery](/treatments/surgical-oncology/tumour-removal-surgery/), or other treatment based on stage and location.

Seek prompt dermatology review for a new, widening, irregular, or unevenly coloured nail streak; pigment extending onto nearby skin; bleeding, ulceration, persistent pain, or a nail that is lifting without a clear injury. If melanoma is diagnosed, keep every recommended follow-up visit. Your team may discuss [Sentinel Lymph Node Biopsy](/treatments/diagnostics-and-staging/sentinel-lymph-node-biopsy/) or [Immunotherapy](/treatments/systemic-therapy/immunotherapy/) when clinically appropriate.

Ask whether the pigment needs a biopsy, what the procedure will involve, how the result guides treatment, and which changes should prompt an earlier call. Ask who will coordinate skin, nail, and cancer follow-up, and keep a record of new symptoms or changes.