A method of assessing a tissue sample includes the steps of::1) splitting source electromagnetic radiation into:a) sample arm radiation directed in a Z direction toward a sample thereby illuminating the sample at a first selected XY coordinate pair of the sample, andb) reflector arm radiation directed toward a reflector so that the reflector arm radiation travels a path length2) interfering sample-scattered electromagnetic radiation with reflector-reflected electromagnetic radiation thereby establishing an interference pattern associated with the sample3) comparing the sample interference pattern to a reference interference pattern and4) reaching a conclusion about the sample based on the comparison.