Fig. 1.

Macroscopic spectral imaging of atypical nevi. (A) Photography, spectral images, and histology of an atypical nevus and a melanoma in situ arising in the nevus. (a, b) 35 mm photographs of the melanocytic lesion are shown. A red-green-blue (RGB) image was derived from the spectral cube of the melanocytic lesion (c). The marked pixels in the RGB image were used to select spectra for classification. In the spectral image (d), the area pseudocolored blue represents the spectrally segregated region containing the melanoma in situ. The H&E-counterstained tissue sections (e) and (f) depict the histology of the atypical nevus (e) and the melanoma in situ (f). (B) RGB and spectral image of a melanoma in situ arising adjacent to a scar from a nevus punch biopsy. An RGB image (a) and a pseudocolored macroscopic spectral image (b) show an area containing a scar and adjacent to it, a melanoma in situ. In the spectral image (b), the spectrally segregated regions assigned the pseudocolor green correspond to tissue sections that were diagnosed by histopathology to contain melanoma in situ.