Observation of periodic fine structure in reflectance from biological tissue: A new technique for measuring nuclear size distribution

We report observation of a fine structure component in backscattered light from mucosal tissue which is periodic in wavelength. This structure is ordinarily masked by a diffusive background. We have identified the origin of this component as being due to light which is Mie scattered by surface epithelial cell nuclei. By analyzing the amplitude and frequency of the fine structure, the density and size distribution of these nuclei can be extracted. These quantities are important indicators of neoplastic precancerous changes in biological tissue.