Invasive Ductal Carcinoma (Breast)
Overview
Plain-Language Overview
Invasive Ductal Carcinoma (IDC) is a type of breast cancer that begins in the milk ducts and then spreads into the surrounding breast tissue. It affects the breast tissue and can interfere with normal breast function. IDC is the most common form of breast cancer, making up about 70-80% of all cases. This cancer can form a lump or mass that may be felt during a physical exam or seen on imaging tests. It can also cause changes in the skin or nipple, such as dimpling or discharge. If untreated, IDC can spread to nearby lymph nodes and other parts of the body, impacting overall health. Early detection is important for better outcomes.
Clinical Definition
Invasive Ductal Carcinoma (IDC) is a malignant neoplasm originating from the epithelial cells lining the breast milk ducts that has invaded beyond the ductal basement membrane into the surrounding stromal tissue. It is characterized by infiltrative growth of atypical ductal cells forming irregular glandular structures. IDC is the most common histologic subtype of breast cancer and is associated with mutations in oncogenes and tumor suppressor genes such as TP53 and BRCA1/2. The tumor often expresses hormone receptors (estrogen and progesterone receptors) and may overexpress HER2/neu, which influences prognosis and treatment. Clinically, IDC presents as a palpable mass, skin changes, or nipple abnormalities and carries a risk of regional lymph node metastasis and distant spread. Its diagnosis and management are critical due to its potential for aggressive behavior and impact on survival.