We performed fluorescence excitation - emission spectroscopy on 20 patients undergoing surveillance or surgery in the clinic and in the OR at New England Medical Center, Otolaryngology Head and Neck Surgery. Measurements were made on 26 clinically abnormal sites and contra lateral sites. After the measurements, lesions were removed for pathological examination. So far we have studied 8 benign, 4 dysplasia, and 12 malignant lesions in buccal mucosa, tongue, floor of mouth, lip, 2 soft palate, retromolar trigone and alveolus. The data are being analyzed.