Caution regarding melanoma following laser treatment of pigmented skin lesions
It is of critical importance to have a confident diagnosis of a coloured skin lesion prior to laser being performed. A study published recently in The Journal of Dermatology reported 11 patients with a melanoma diagnosed in a region previously treated with laser therapy. In 9 cases, no biopsy was taken prior to laser. In the other two, pre-laser biopsy had shown a benign lesion. Four of the 11 patients progressed to stage IV disease and at least one died of melanoma.
This emphasises the very real difficulty in the diagnosis and treatment of pigmented skin lesions. It is imperative that a reliable diagnosis is established prior to any laser treatment. Each case is different, but a biopsy should be considered. As demonstrated with this series however, a partial biopsy of a pigmented lesion is not always representative of the lesion as a whole.
A high level of suspicion and caution should be exercised before making the decision to have a brown mark lasered off. We see cases, not infrequently, where the laser has removed the pigment but not the melanoma cells themselves. This can delay the subsequent diagnosis and treatment of the melanoma - with potentially fatal consequences. Pigmented skin lesions are not necessarily a mere cosmetic issue, and must be treated with the respect they deserve.