This lecture describes a single case that represents a very important group of breast cancers we call duct forming invasive carcinoma / carcinoma of ductal origin (DAB). Dr. Lana Rezan donated this tragic case for teaching. We strongly recommend for every member of the diagnostic and therapeutic teams to watch it and learn from it. The most important message is that the current histopathologic terminology calls this group of highly fatal breast cancers "DCIS". This misnomer misleads the surgeons who perform breast conserving surgery on these cases, often leaving a part of the aggressive cancer behind that harms the patient. The pathologists determine the immunohistochemical biomarkers from the associated acinar adenocarcinoma of the breast which misleads the oncologists. The teaching points of this video meant to be an eye-opener for everybody diagnosing and treating breast cancer patients.