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, and b) reflector arm radiation directed toward a reflector so that the reflector arm radiation travels a path length; 2) interfering sample-scattered electromagnetic radiation with reflector-reflected electromagnetic radiation thereby establishing an interference pattern associated with the sample; 3) comparing the sample interference pattern to a reference interference pattern; and 4) reaching a conclusion about the sample based on the comparison.