(a) UV-PAM image of a fixed breast tumor specimen. (b–d) Magnified images of the areas highlighted with dashed boxes in (a) (e) H&E stained image obtained by optical microscopy. (f–g) Magnified image of the areas highlighted with dashed boxes in (e). The areas highlighted with the blue dashed lines in (a, e) represent tumor regions. IDC, invasive ductal carcinoma; DCIS, ductal carcinoma in situ; CN, cell nuclei; and PA, photoacoustic. Reprinted from Ref. [23]. © The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution Non Commercial License 4.0 (CC BY-NC) http://creativecommons.org/licenses/by-nc/4.0/.