All of us in primary care who have been faced with the dilemma of ascertaining whether a particular lesion on the skin of a patient is benign or malignant know that, in the absence of a biopsy, we can rarely respond with certainty. Of course, we would rather not biopsy a benign lesion unnecessarily because of time, expense, discomfort, and cosmetic concern for the patient. On the other hand, we don’t everwant to mistakenly allow a cutaneous malignancy, particularly malignant melanoma, to stay on the skin without being identified.

Gerami et al report on the use of a skin patch to diagnose melanoma on the basis of mRNA profiles. Having obtained mRNA “signatures” from multiple prior cases of malignant melanoma in their study sample, subjects had an adhesive patch placed above the lesion in question, which was vigorously rubbed to create adhesion of skin cells to the patch, which were then analyzed for mRNA. After removing the patch, lesions were biopsied to confirm their pathology.

The sensitivity of skin patch-retrieved mRNA diagnosis for melanoma was 97.6%. Hence, having a negative skin patch mRNA test essentially excluded melanoma. The authors point out that such technology could meaningfully reduce unnecessary skin biopsies for questionable lesions.