Light sheds light on cancer--distinguishing malignant tumors from benign tissues and tumors.

Difference in fluorescence spectra from human malignant and benign tumors, benign and normal breast tissues were measured. Spectral histograms from 40 samples show the diagnostic possibilities of this optical technology. Fluorescence from model fluorophores (nucleotides, amino acids, and proteins) were used to speculate on the sources of marked features of the tissue fluorescence.