Researchers have developed a new non–invasive technique which can accurately detect malignant melanoma without a biopsy. The report, published online in Nature Scientific Reports, showed that a special technique using a laser to detect the subtle differences in blood flow beneath the skin enabled researchers to tell the difference between malignant melanoma and non–cancerous moles. During the study, led by Lancaster University and Pisa University in Italy, 55 patients with atypical moles agreed to have their skin monitored by researchers at Pisa University Hospital using a laser Doppler system. The laser Doppler was used to record the complex interactions taking place in the minute blood vessels beneath their suspicious mole for around 30 minutes. The fluctuations in recorded signals were then analysed using methods developed by physicists at Lancaster University. The patients in the study then went on to have their moles biopsied and the results were compared with the information obtained – noninvasively – using the laser Doppler scan. The laser Doppler signal correctly identified 100% of the patients with malignant skin.