Histology. Right breast: (a) Lobular carcinoma in situ. (b) Amplified section with invasive carcinoma, with epithelial markers. (c) Lobular carcinoma in situ and with an invasive component. Left breast: (d) Sarcoma of the stroma and ductal structures (arrow) of normal mammary tissue. (e) Amplified section revealing mammary sarcoma with bundles and cells (left) in many phases of mitosis. (f) Stromal sarcoma section of mammary stroma stained with cytokeratin (ducts) and negative for tumor tissue.