Figure 1 .

Breast cancer anatomy. Schematic representation of mammary gland anatomy and cancer development. The majority of breast tumors develop in the terminal duct lobular unit, 80% starting among ductal cells. Initially, the duct suffers a benign hypertrophic growth of cells that can progress into ductal carcinoma in situ (DCIS). In this phase the neoplasm is confined within the duct’s lumen and it is still clinically benign. Cancer cells can cross the duct wall’s boundaries, invading nearby tissues (IDC) and metastasizing.