Fig. 8: In vivo volumetric multimodality microscopy imaging of a melanoma in situ lesion from the upper back under 880 nm fs laser excitation (contrast-enhanced along the depth direction).

a The yz plane overview of the tissue volume with a dimension of 200 µm × 200 µm × 5 mm encompassing the lesion (left), its border (middle), and the adjacent normal tissue (right). b Zoomed-in yz plane images of the above three selected sub-volumes as marked by white boxes in (a) for detailed examination The three boxes from left to right correspond to cancerous, border, and adjacent normal tissue respectively. c, d Horizontal views of the three sub-volumes at five depths as marked in (b). Note that the exact depth of D1–D5 in the three sub-volumes is selected differently to show the most typical morphological features. The cancerous zone shows dendritic pagetoid cells (white arrowheads) and aggregated atypical cells (white arrows) with nonspecific patterns (the dashed circle). The border zone is filled with bright, round-shaped cells forming dermal papillae that contain collagen signals. The normal tissue has abundant collagen signals with clearly defined dermal papillae. Color is coded in green for RCM, red for TPF, and magenta for SHG. Scale bar: 100 µm.