Figure 2

Lymphocyte infiltration within in situ breast and prostate cancer tissues. Paraffin-embedded human breast (A-B) and prostate (C-D) tissue sections were double immunostained for SMA (red) plus LCA (brown) or CK34βE12 (a basal cell marker; red) plus LCA. Note that although these in situ breast and prostate tumor nests (stars) are almost completely surrounded by infiltrating immune cells (arrows), a vast majority of the tumor cells are physically separated from the surrounding infiltrating immune cells by the tumor capsule (the myoepithelial or basal cell layer) (arrowheads). A and C: 100X B and D: a higher (300X) magnification of A and C, respectively.