Brown Line on Nails: A Silent Killer? Spotting Subungual Melanoma Early

• A vertical brown or black streak on nails, medically termed 'subungual melanoma,' can be a rare and dangerous form of skin cancer.
• Unlike common skin cancers, subungual melanoma can occur without sun exposure and originates from the nail matrix.
• Key warning signs include a dark streak widening over time, color spreading to surrounding skin, or persistent marks unlike typical nail injuries.
• Early detection is crucial; if caught early, 90-95% of cases can be cured, but it spreads rapidly if untreated.
• Regular self-examination of nails, especially for single-digit discoloration or marks wider than 3mm, is vital for timely diagnosis.