Fig. 5

The diseased duct. A low-magnification view of the mammary gland from the tumor-free right inguinal (#4) mammary fat pad of a nulliparous 106-week-old tumor-bearing 129:Stat1 ^−/− female showing four engorged ducts (asterisks) coursing through the mammary fat pad (a). LN Lymph node. Scale bar = 2 mm. Note that the large oval pale (LOP) cell-forming multiple aberrant side buds are restricted to one duct (green box) (b) and have a nodular profile (arrows). Other main stem ducts and their branches have smooth outlines and a normal basal and luminal bilayered epithelium (arrowheads). In addition, Additional file 2: Figure S3 shows quantitation of the distribution of LOP cells. The DNA sequences of laser capture microdissection from the diseased duct within the green box showed three different single-nucleotide variations in the prolactin receptor (PRLR) gene. A higher-magnification image shows the solid abortive side buds filled with LOP cells of the diseased duct. Scale bar = 400 μm. Figure 6c shows a higher-magnification view of progesterone receptor-stained LOP cells in the solid nodules of the same duct