Breast cancer is cancer that begins when breast cells start multiplying and out of order. When these cells outgrow, they create a tumor which can be seen using an x-ray or simply felt as a lump. The tumor formed is considered malignant (cancer) when the cells grow and spread into the nearby tissues.(1)

This type of cancer happens in females more, but there are minimal chances that men can also get this cancer. There are different parts of the breast from which cancer can start. Nonetheless, most of these cancers start in the duct carrying milk to the nipple, and it’s referred to as ductal cancer.

Lobular cancers begin in the glands making the breast milk. There are also other forms of breast cancer that rarely occurs. It is the most common invasive cancer occurring in the females globally. (2)

What Are The Types Of Breast Cancer?

In some forms, the cancer cells may fail to form a tumor or lump at all. Those tumors that have not spread are referred to as In Situ, while those that have spread or invaded the nearby breast tissues are called Invasive or infiltrating cancers, and they include:

  • Ductal carcinoma in situ (DCIS): it’s a non-invasive or pre-invasive type of cancer
  • Invasive/Infiltrating Ductal Carcinoma (IDC): infiltrating ductal carcinoma (IDC) begins in the breast’s milk duct. It is the most common type of breast cancer.
  • Invasive/Infiltrating Lobular Carcinoma (ILC): this type begins in the glands or lobules producing milk. It can also spread to other body parts like the IDC. (3)

These are the subtypes of invasive carcinoma:

  • Adenoid cystic/adenocystic) Carcinoma
  • Low-Grade Adenosquamous Carcinoma – a form of metaplastic carcinoma)
  • Medullary Carcinoma
  • Mucinous/Colloid) Carcinoma
  • Papillary Carcinoma
  • Tubular Carcinoma

The sub-types that have same diagnosed with standard infiltrating ductal carcinoma include:

  • Metaplastic Carcinoma
  • Micropapillary Carcinoma
  • Mixed carcinoma – have both invasive ductal and lobular features

Other Common Types Of Breast Tumor

Inflammatory breast cancer is an uncommon type of cancer accounting for about 1 – 3 percent of all the occurrences of cancers of the breast.

  • Paget disease of the nipple: It is a kind of cancer that starts in the breast ducts then spreads to the nipple skin and the areola. However, Paget is a rare type that accounts for only about 1% of all cases of cancer of the breast.
  • Angiosarcoma: Angiosarcoma is a type of cancer that rarely happens in the breasts. Furthermore, it starts in the cells lining blood or lymph vessels.
  • Phyllodes tumor: Lastly, these are also an uncommon type of breast tumors. It develops in the stroma or the connective tissue of the breast, unlike the carcinomas that develop in lobules or ducts. (4)

References