What should you know about malignant melanoma of the nail?

Nail melanoma, also called subungual melanoma, develops in pigment-producing cells beneath the nail or near its growth area. It may look like a brown or black stripe that becomes wider, develops uneven colour, or has blurred sides. Pigment can extend onto the surrounding skin, and the nail may split, lift, bleed, or form a persistent sore. A dark nail can also follow an injury, fungal infection, medication effect, or a harmless pigment pattern. Because these causes overlap visually, a clinician must examine the nail, surrounding skin, and other nails before deciding whether a biopsy is needed.

Arrange a dermatology review for a new stripe, a mark affecting one nail, change in width or colour, pigment reaching the cuticle, or a nail that is lifting without a clear injury. Remove nail polish before the visit and bring older photographs if available. Avoid drilling, scraping, or repeatedly trimming the discoloured area. A biopsy may sample the nail bed or growth region; the result guides whether surgical excision or wider skin cancer surgery is appropriate. Healing and nail regrowth can take time, so ask about dressing care and hand or foot use after treatment.

Seek prompt review for bleeding, a non-healing sore, increasing tenderness, swelling, pus, or rapid nail destruction. Urgent care is appropriate for spreading redness with fever, severe throbbing pain, or bleeding that will not stop with gentle pressure. Do not wait for discomfort: early nail melanoma may cause no pain, and a changing appearance is enough reason to arrange examination.

Ask whether the stripe’s pattern suggests trauma, infection, or a pigment tumour; whether dermoscopy or biopsy is needed; and what part of the nail will be sampled. Discuss possible nail changes after treatment, wound protection, pathology timing, lymph-node assessment, and the follow-up plan.