Optical UV-VIS-NIR spectroscopy of benign, dysplastic and malignant cutaneous lesions ex vivo

Optical spectroscopic measurements with a few different modalities have been performed namely autofluorescence, transmission and diffuse reflectance spectroscopies in ultraviolet, visible and near-infrared spectral ranges. The investigated samples were cutaneous tumours ex vivo, obtained after surgical removal and kept in a formalin solution and histological sections from biopsy tissue samples, which were routinely processed for histological analysis. Comparative spectral data for benign, dysplastic nevi and pigmented malignant melanoma lesions, as well as for non-melanoma skin tumour - basal cell carcinoma, squamous cell carcinoma and benign non-melanin pigmented pathologies - heamangioma and seboreic veruca are presented in the current report. Fluorescence spectra obtained reveal statistically significant differences between the different benign, dysplastic and malignant lesions by the level of emission intensity, as well by spectral shape, which are fingerprints applicable for differentiation algorithms. In reflectance and absorption modes the most significant differences are related to the influence of skin pigments - melanin and hemoglobin, less pronounced is the influence of structural proteins, such as collagen and keratin. Transmission spectroscopy mode gives complementary optical properties information about the tissue samples investigated to that one of reflectance and absorption spectroscopy.