Currently most cancers, including breast cancers, are removed without any intraoperative margin control. Post-operative methods inspect 1-2% of the surgical margin and are prone to sampling errors. The present invention relates to an optical imaging system that will enable evaluation of the surgical margin in vivo and in real-time. The invention provides for simultaneous fluorescence and fluorescence polarization imaging. The contrast of the acquired images will be enhanced using fluorescent agents approved for diagnostic use in patients. As the staining pattern of fluorescence images is similar to that of histology, and the values of fluorescence polarization are significantly higher in cancerous as compared to normal cells, the invention provides for further improvements in diagnostic methods. The systems and methods can be applied to the intra-operative delineation of cancerous tissue.