Vibrational spectroscopy for molecular characterisation and diagnosis of benign, premalignant and malignant skin tumours.

Understanding the molecular, cellular and tissue changes that occur during skin carcinogenesis is central to cancer research in dermatology. The translational aspects of this field--the development of clinical applications in dermatology from the laboratory findings--aim at improving clinical diagnosis, monitoring and treatment of skin cancer. Vibrational spectroscopy, both infrared (IR) and Raman spectroscopy, would be helpful in achieving those goals, since it has been shown to have potential in characterising and discriminating tumour and dysplastic tissue from normal tissue. Clinically differential diagnosis of skin tumours is often difficult and a histopathologic analysis of skin biopsies remains the standard for diagnostic confirmation. We review and update the literature on the subject, demonstrating that the IR and Raman spectra of skin tissues provide valid and useful diagnostic information about a number of skin tumours. We also include a survey of introduced sampling methods for IR and Raman spectroscopy in dermatology, and additionally describe the differences between microscopic, macroscopic and fibreoptic diagnosis of skin cancer. Although in its early stages, we remain optimistic that vibrational spectroscopy has the potential to be fully accepted as a rapid screening tool with sufficient sensitivity and specificity for non-destructive in vitro, ex vivo and in vivo analyses by the dermatological community. Further progress toward molecular characterisation of skin cancer by vibrational spectroscopy would have important research and clinical benefits in dermatology.