Figure 2

Four histologically differing zones identified in haematoxylin-eosin stained skin porcine melanoma: (A) growing melanoma tissue (GMT), (B) melanoma tissue with early destruction of melanoma cells (early spontaneous regression-ESR), (C) melanoma tissue with late destruction of melanoma cells (late spontaneous regression-LSR), (D) fibrous tissue (FT) with a few remaining melanoma cells. Scale bar = 50 μm (* = melanoma cells; + = cellular debris from damaged melanoma cells; x = fibrous tissue).