A micro-Raman spectrometer system for use in differentiating tumor lesions from normal skin detects specific characteristics of Raman spectra indicative of cancer. A peak at 899 cm ' and a higher intensity region in the 1325 cm to 1330 cm range indicate the presence of tumors. The spectrometer system may be applied for skin cancer detection and for mapping the margins of lesions. Cancer detection methods as described herein have achieved diagnostic sensitivity of 95.8% and specificity of 93.8%.
