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The purpose of this study was to extract scatter parameters related to tissue ultra-structures from freshly excised breast
tissue and to assess whether evident changes in scatter across diagnostic categories is primarily influenced by variation
in the composition of each tissues subtypes or by physical remodeling of the extra-cellular environment. Pathologists
easily distinguish between epithelium, stroma and adipose tissues, so this classification was adopted for macroscopic
subtype classification. Micro-sampling reflectance spectroscopy was used to characterize single-backscattered photons
from fresh, excised tumors and normal reduction specimens with
sub-millimeter resolution. Phase contrast microscopy
(sub-micron resolution) was used to characterize forward-scattered light through frozen tissue from the DHMC Tissue
Bank, representing normal, benign and malignant breast tissue, sectioned at 10 microns. The packing density and
orientation of collagen fibers in the extracellular matrix (ECM) associated with invasive, normal and benign epithelium
was evaluated using transmission electron microscopy (TEM). Regions of interest (ROIs) in the H&E stained tissues
were identified for analysis, as outlined by a pathologist as the gold standard. We conclude that the scatter parameters
associated with tumor specimens (Npatients=6, Nspecimens=13) significantly differs from that of normal reductions
(Npatients=6, Nspecimens=10). Further, tissue subtypes may be identified by their scatter spectra at sub-micron resolution.
Stromal tissue scatters significantly more than the epithelial cells embedded in its ECM and adipose tissue scatters much
less. However, the scatter signature of the stroma at the sub-micron level is not particularly differentiating in terms of a
diagnosis.
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