Fig. 1. Differential CD68⁺ and CD163⁺ macrophage recruitment to primary melanoma lesions.

The number of CD68⁺ and CD163⁺ cells was determined by immunohistochemistry in primary melanoma tumours. The number of positive cells was counted in the peritumoural and intratumoural regions. CD68⁺ and CD163⁺ cells were shown to be differentially recruited (a, b). Intratumoural CD163⁺ macrophage infiltration was positively correlated to Breslow depth (c), while intratumoural CD68⁺ macrophage infiltration showed no significant correlation (d). Tumours with no peritumoural CD68⁺ macrophages had a greater Breslow depth (e), and decreased numbers of peritumoural CD68⁺ macrophages were seen in ulcerated tumours (f).