1. A method for classifying a tissue sample of a biopsy specimen into one of a plurality of classes, the method comprising: receiving a light from at least one location of the tissue sample comprising a plurality of chromophores, wherein the received light comprises at least one of an attenuated illumination light and a re-emitted light; processing a spectrum of the received light to determine a feature for each of the chromophores in the at least one location of the tissue sample; estimating a Z-score for each of the chromophores based on the determined feature; and classifying the tissue sample into one of the plurality of classes based on the estimated Z-score for each of the chromophores.