Breast Cancer Types
The type of breast cancer is determined by which type of cell in the breast becomes cancerous.
The most common types include:
Breast Cancer DCIS
Facts about ductal carcinoma in situ (DCIS):
- Ductal carcinoma in situ (DCIS) refers to cancer of the milk ducts that is confined to the milk ducts and has not spread outside the ducts.
- DCIS tends to spread along the milk ducts.
- DCIS also can be multifocal: meaning that it can appear in more than one portion of the breast.
- Overall, DCIS is a more treatable form of cancer than infiltrating (or invasive) ductal carcinoma.
- When DCIS is small and localized to one area, treatment will usually involve simple lumpectomy.
- Radiation therapy may be offered in some cases following lumpectomy.
Breast Cancer Ductal Carcinoma
Facts about infiltrating ductal carcinoma:
- Infiltrating ductal carcinoma accounts for up to 80% of all breast cancers in women.
- This is a form of ductal carcinoma that has spread beyond the milk ducts.
- This form of breast cancer typically causes a hard well-defined lump in the breast.
- Infiltrating ductal carcinomas will often spread to the lymph nodes under the arm.
Breast Cancer LCIS
Facts about lobular carcinoma in situ (LCIS):
- Lobular carcinoma in situ, or LCIS, is not an actual cancer, but a marker for potential invasive breast cancer.
- The finding of LCIS on a breast biopsy put the patient at a risk of 1% per year of developing cancer in either breast.
- If a cancer develops from the LCIS, it is more commonly ductal carcinoma as opposed to lobular carcinoma.
- Women with LCIS may not need to have the lesion removed. They will however require close physician follow-up that includes yearly physician exams and mammography to make sure their condition does not change. Monthly breast self examination is also recommended.
Breast Cancer Medullary Carcinoma
Facts about medullary carcinoma of the breast:
- A rare subtype of ductal carcinoma, a form of breast cancer that arises from the milk ducts.
- Medullary carcinomas tend to be large and make up only 5-7% of all cases.
- Can occur at any age, but usually affects women between the age of 40 and 55.
- More common in women with the BRCA1 gene mutation.
- More common in Japan than the United States.
Breast Cancer Mucinous Carcinoma
Facts about mucinous carcinoma:
Breast Cancer Paget's Disease
Facts about Paget's disease:
Breast Cancer Tubular Carcinoma
Facts about tubular carcinoma:
Continue to Breast Cancer Anatomy
- Aiello EJ, Buist DS, White E, Seger D, Taplin SH. Rate of breast cancer diagnoses among postmenopausal women with self-reported breast symptoms. J Am Board Fam Pract. 2004 Nov-Dec;17(6):408-15. 
- Collaborative Group on Hormonal Factors in Breast Cancer: Breast cancer and hormone replacement therapy: collaborative reanalysis of data from 51 epidemiological studies of 52,705 women with breast cancer and 108,411 women without breast cancer. Collaborative Group on Hormonal Factors in Breast Cancer. Lancet 1997 Oct 11; 350(9084): 1047-59. 
- Giordano SH. A review of the diagnosis and management of male breast cancer. Oncologist. 2005 Aug;10(7):471-9.