What it is and where it starts
Nail melanoma originates in melanocytes of the nail unit, often in the matrix, the structure that produces the nail plate. The term describes a location and may overlap with acral lentiginous melanoma. It is not simply a mark deposited on the nail: assessment also concerns the matrix, nail bed and surrounding folds.
It can affect fingers or toes, often the thumb or great toe. It is seen mainly in adults and older people, but age cannot exclude it. Both sexes and all skin colours can be affected. It accounts for a relatively larger proportion of melanomas in some dark-skinned populations; this is not the same as a higher overall melanoma incidence in those populations.
Historical percentages for ethnic groups cannot be applied indiscriminately to every country. Nail melanoma does not have the same relationship with sun exposure as forms typical of sun-exposed skin. A remembered injury neither establishes the cause of the lesion nor excludes melanoma.
Pigmented bands and other presentations
One possible presentation is a longitudinal brown or black band, known as longitudinal melanonychia, appearing or changing on a single nail. Progressive widening, different colours, irregular borders or greater width near the matrix deserve attention. Nail distortion, lifting or destruction, bleeding and a growth beneath the plate can also occur.
Pigmentation of the surrounding nail-fold skin is called Hutchinson’s sign. It can increase suspicion but is not exclusive to melanoma: benign conditions and apparent pigmentation also occur. Its absence does not exclude disease. No individual sign replaces an overall assessment.
Poorly pigmented or amelanotic nail melanomas may resemble a pyogenic granuloma, an inflammatory lesion or an ingrown nail. A persistent growth that enlarges, bleeds or fails to heal needs reassessment even without a dark band.
From benign causes to biopsy
Bruising, matrix moles, physiological pigmentation, medicines and other conditions can cause colour changes. Pigmentation of several nails may suggest a benign explanation but must be interpreted alongside the history and appearance of each lesion. Simply waiting for presumed bleeding to disappear is insufficient when uncertainty remains.
Nail dermoscopy helps assess the arrangement and regularity of lines, residual pigment and structural changes. Histological examination confirms the diagnosis when biopsy is indicated. Sampling should be planned by an experienced specialist according to the origin and extent of the lesion; it does not automatically require removal of the entire matrix.
An inadequate sample may miss the most important part of a lesion. Diagnostic accuracy must be balanced against the risk of permanent nail damage, with an explanation of the procedure, possible outcomes and need for further sampling. Do not attempt to treat or remove a suspicious lesion yourself.
Surgery, staging and follow-up
Treatment depends on invasion, Breslow thickness, ulceration and involvement of deeper structures. Selected early lesions may be considered for digit-preserving surgery. Amputation is not an automatic consequence of diagnosis; it may be needed when disease extent, including possible bone involvement, prevents adequate removal with functional preservation.
Possible sentinel lymph node biopsy is based on risk assessment in invasive melanoma. Lymph node removal is not mandatory for every nail melanoma. Higher-risk or advanced disease may require systemic treatment according to stage and biological features.
Subsequent care considers healing, function, reconstruction and cancer surveillance. Include every nail during skin self-examination and report new or persistent changes. Neither prognosis nor treatment can be determined from a photograph of the nail alone.
Sources and update
- National Cancer Institute — Melanoma Treatment (PDQ)
- ESMO — Cutaneous melanoma: Clinical Practice Guideline (2025)
- DermNet — Nail melanoma
Editorial revision: 16 October 2026. This information does not replace medical assessment.