When we talk about breast cancer, we often assume that there is only one type. There are actually as many as fifteen different 'types' of breast cancer. Some types of breast cancer grow more quickly then others, and some may progress unnoticed for months or years. Some types are easily found with the palpation during a breast self-examination, some are found with a mammogram, and others are found only with ultrasound, MRI or other advanced techniques.

Cancer is named for the location of the body or the body part in which it originates. If a cancer starts in the breast, it is one of the variations grouped under the classification of breast cancer, and even if it metastasizes and spreads to the lungs, it will still be breast cancer. The different types of breast cancer are named for several things:

    - Location in the breast: If the cancer first appears in a milk duct, it may be referred to as a Ductal Carcinoma. Lobular Carcinomas will start in the lobule of the breast.

    - Amount of involvement: If the cancer starts in the duct, and has not progressed far enough to have come through the ductal wall, it is refered to as being in situ, as in Ductal Carcinoma in Situ. If it has gone through the ductal wall, it is referred to as Invasive Ductal Carcinoma or Infiltrating Ductal Carcinoma.

    - Appearance of the tumor: Sometimes the pathology report uses a name that merely suggests that it appears to resemble another object., such as Medullary Carcinoma that resembles the color of brain tissue.

    - Whether or not it has spread to other parts of the body. If the term metastatic precedes the name of the cancer, that indicates that it has metastasized, (spread into other parts of the body).

    - If cancer is related to a gland (a breast is a gland, and some ducts in the breast are considered to be glands) it may be referred to as Adeno-carcinoma.

More then one type of breast cancer can be present in any one case of breast cancer. Some examples of these  types are as follows:

Ductal Carcinoma In Situ (DCIS) or Intraductal Carcinoma or noninvasive carcinoma
First developing in the milk ducts, it can easily enlarge and grow through the ductal wall to reach the fatty tissue surrounding the ducts. If this occurs, it is very easy for it to be picked up by the blood circulatory or the lymphatic circulatory system and be spread throughout the body. Accounts for about eleven percent of the breast cancer cases.

Infiltrating Ductal Carcinoma or Invasive Ductal Carcinoma
This began in the ducts, but has grown through the ductal wall into the surrounding breast tissue. This has about a fifteen percent chance of occurring in the other breast. Considered to be the most common type of breast cancer, this accounts for about sixty one percent of the breast cancer cases.

Lobular Carcinoma In Situ (LCIS)
First developing in the lobes (lobules or acini) that produce milk, it can easily enlarge and grow through the outer wall of the lobe to reach the surrounding fatty tissue. If this occurs, it is very easy for it to be picked up by the blood circulatory or the lymphatic circulatory system and be spread throughout the body. Accounts for about two percent of the breast cancer cases.

Infiltrating Lobular Carcinoma or Invasive Lobular Carcinoma
This began in the lobules, but has grown through the lobular wall into the surrounding breast tissue. This has about a twenty percent chance of occurring in the other breast. Accounts for about six percent of the breast cancer cases.

Medullary Carcinoma
A soft, malignant tumor at or near the surface of the skin, having the color of brain tissue,  with little or no fibrous tissue. Accounts for about six percent of the breast cancer cases.

Mucinous Carcinoma or Colloid Carcinoma
A soft, malignant tumor at or near the surface of the skin, with a gelatinous consistency that produces a mucous.  Accounts for about three percent of the breast cancer cases.

Inflammatory Carcinoma or Inflammatory Breast Cancer (IBC)
This is receiving an inordinate amount of "press coverage" lately for some reason. Accounting for about one percent or less of all breast cancers, it is the most aggressive type of cancer. It is difficult to treat, and it spreads very quickly.
This term is also used to indicate that the tumor site exhibits indications of an inflammation, such as redness, heat, swelling and pain. This can also refer to a spreading of cancerous growth due to surgical disruption of a tumor.

Tubular Carcinoma
A soft, malignant tumor that looks like tubules or ductwork. This is very unusual and is present in about one percent of the  breast cancer cases.

Papillary Carcinoma
This has cells that appear to be like small fingers or papules. Accounts for less then one percent of the breast cancer cases.

Adeno-carcinoma or Adenocystic Carcinoma
A general term referring to cancer of a gland or glandular tissue. Accounts for less then one percent of the breast cancer cases.

Apocrine 
pertaining to a gland that secretes a substance, such as a specialized sweat gland. Accounts for less then one percent of the breast cancer cases.

Scirrhous Carcinoma or Carcinoma Fibrosum
A hard, fibrous, particularly invasive tumor in which the malignant cells occur singly or in small clusters or strands in dense connective tissue. Accounts for less then one percent of the breast cancer cases.

Carcinosarcoma
A malignant neoplasm composed of carcinomatous and sarcomatous cells. Accounts for less then one percent of the breast cancer cases.

Squamous
Referring to a tumor that has platelike or scaly cellular growth, or is covered with scales. Accounts for less then one percent of the breast cancer cases.

Paget's Disease
This has received an inordinate amount of "press coverage" in the last few years for some reason. A crusty or scaly condition that begins in the ducts near the breast surface. It usually spreads out of the duct, onto the surface of the areola. A rare type of breast cancer, it is often ignored and misdiagnosed as a simple case of eczema. Aggressive treatment is usually called for. Accounts for less then one percent of the breast cancer cases.