Differentiation of malignant skin neoplasms using Raman spectroscopy with an excitation wavelength of 532 nm in the high-wavenumber region

Confocal scanning Raman and fluorescence microspectroscopy are structure-sensitive optical techniques that allow for the non-invasive analysis of biomarkers in skin tissue. Distinct spectral differences were observed in the Raman spectra of basal cell carcinoma and squamous cell carcinoma compared to healthy skin and papilloma. Our analysis of Raman and fluorescence spectra at an excitation wavelength of 532 nm enabled us to propose two spectral criteria: intensity ratios for the bands at 2880 and 1445 cm$^{-1}$ , and for the bands at 2930 and 1445 cm$^{-1}$. These criteria are based on differences in cell membrane lipid fluctuations, which serve as biomarkers. They allowed for the differentiation of healthy skin from basal cell carcinoma, squamous cell carcinoma, and papilloma with a sensitivity and specificity of more than 90%, demonstrating high clinical significance in the differential diagnosis of skin neoplasms.