Sarah Cannon - November 03, 2017

Breast Cancer Types

There are many types of breast cancer. If you or a loved one is diagnosed with breast cancer, you may hear terms like “adenocarcinoma” and “in situ” and wonder what they mean. Below you will learn about the two most common types of breast cancer and how they act in the body:

  1.  Ductal Carcinoma In Situ

Ductal carcinoma in situ (DCIS) occurs when cells that line breast ducts change and become cancer cells. This type of cancer remains in its original place (in situ). These cancer cells only appear in the duct and not the surrounding breast tissue. 

  1. Invasive Breast Cancer

As the title suggests, invasive breast cancer goes beyond its starting point and invades other tissues, or metastasizes. ILC (Invasive lobular carcinoma) begins in the breast’s milk glands and attacks other breast tissues as well. ILC is considered an adenocarcinoma because the cancerous cells populate in the gland. If your cancer is an IDC (invasive ductal carcinoma), you are among the 8 in 10 women with breast cancer who share this diagnosis. Although many women have IDC, there are many sub-types.  We’ve outlined a few below:

  • Medullary Carcinoma: common in women with the BRCA1 mutation, this sub-type looks more aggressive than it behaves, meaning that it tends to spread slowly. 
  • Papillary Carcinoma: occurring in post-menopausal women, this IDC usually has finger-like projections and appears with DCIS.
  • Cribriform Carcinoma: when cancerous cells make a nest-like structure between milk-ducts and lobules invading the connective tissue, or stroma.  


American Cancer Society - Breast Cancer Diagnosis - Types - Tubular