RADIOLOGY: BREAST: Case# 32945: INFILTRATING DUCT CARCINOMA. 50 Year old female with a palpable breast mass. Close up view of the mammogram reveals a single mass with spiculated borders. The spiculated or stellate mass is probably the most pathognomonic mammographic sign of breast cancer. Most such lesions are infiltrating duct carcinomas. The spiculated borders are caused by a desmoplastic reaction in the tissues surrounding the tumor cells.