What should you know about nail matrix melanoma?

The nail matrix sits beneath the skin at the base of the nail and produces the nail plate. Melanoma there can create a brown or black band that extends along the nail. Pigment may widen, become uneven, involve nearby skin, or cause the nail to split or lift. A dark mark can have other explanations, so appearance alone cannot confirm the diagnosis. A dermatologist may examine the nail and surrounding skin with magnification and may recommend a biopsy of the nail matrix.

Arrange a dermatology assessment for a new or changing pigmented band, especially when it affects one nail or gradually changes. Do not cover it with polish before the visit; take clear photographs in natural light and note when the mark was first noticed. If melanoma is confirmed, treatment commonly involves removing the affected tissue, with further planning based on the biopsy and examination. This can include surgical excision, staging tests, or treatment that reaches melanoma cells throughout the body.

Seek prompt medical review when a nail band is new, widening, irregular, or accompanied by pigment on the surrounding skin, bleeding, pain, or nail distortion. An urgent appointment is sensible if the change is progressing quickly or follows no clear injury. Seek immediate care for heavy bleeding, severe pain, or signs of infection such as spreading redness, warmth, or fever.

Ask whether the pigment appears to arise from the nail matrix, whether a biopsy is needed, and what the procedure may mean for nail growth. You can also ask which staging assessments are appropriate, how the result changes treatment, and how follow-up will monitor the nail and the rest of your skin.