Figure 2.

Crusted, hyperkeratotic, papillated lesion with concave center and shower-glass effect. 6×6mm superficial (top left) mosaic shows black, oil-filled crevasses of a centrally concave lesion. Upper panel inset (green box) shows a 2×2mm submosaic of at the level of stratum spinosum (rimmed by bright stratum spinosum) in papillated areas surrounding the black concavities, where the tissue surface has yet to be reached. Lower panel shows a deeper 6×6mm mosaic and 2×2mm submosaic inset (yellow box) where the majority of the lesion is at the DEJ level, but the base of the concavity is bright, hyper-reflective stratum corneum. This deeper mosaic also illustrates the shower-glass effect, where foci appear dark with loss of resolution due to excessive scattering of light through overlying crusts/hyperkeratosis. The mosaic grid pattern is visible in the larger mosaics.