Figure 1.

Immunohistochemical staining of IL-17-positive macrophages in breast cancer. (a) Tonsil section stained with IL-17 showing IL-17-positive cells: the shape and distribution of these cells indicate they are the macrophages within the germinal centre of the lymphoid follicles (magnification ×200). Staining of IL-17-positive cells in sections from breast cancer: (b) IL-17-positive cells located in the peritumoural areas (magnification ×200); (c) IL-17-positive macrophages characterised by having an oval or irregular shape, a kidney-shaped nucleus and a prominent nucleolus located at the nuclear membrane (arrows and inset) (magnification ×400) – this is a typical example of the level of inflammation scored as 2+; and (d) peritumoural area with dense inflammatory infiltrate showing one giant cell – a large-sized cell with multiple nuclei (arrow & inset) (magnification ×400). In all positive cells, staining was found to be only cytoplasmic and the nuclei are completely negative. (e), (f), (g), (h) Examples of IL-17 and CD68 staining in consecutive sections of breast cancer. Because it was not possible to satisfactorily stain IL-17 and CD68 on the same section, we stained consecutive sections for each antigen. As can be seen, whilst the tumour (T) is negative, the IL-17-positive cells in the surrounding stroma were found in similar areas to the CD68⁺ macrophage (red arrow).